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Ultra-Quiet 120mm fans

120mm fans have enjoyed a massive surge in popularity in recent times, with many case manufacturers now including 120mm fan cutouts as standard. The big advantage of a 120mm fan is that because its blades are larger than most of the other common fan sizes, the fan does not have to spin as quickly in order to produce a given amount of airflow. This means less noise and longer life! With our large range of 120mm fans, there is sure to be a fan to suit any budget and airflow requirement.

To differentiate between standard 3-Pin fans and 4-pin PWM (self adjusting) fans we use PWM in the name of the fan. If it doesn’t say PWM in the name of the fan then it is a standard 3-pin fan.

To convert airflow in cubic feet per minute (CFM) to cubic metres per hour (m³ /h), multiply the CFM figure by 1.7.

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Gelid Solutions 5x Stella ARGB 120mm Fans plus AMBER5 ARGB Controller Combo Pack

13 in stock
5x Stella ARGB 120mm Fans plus AMBER5 ARGB Controller Combo Pack
$42.89
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  • Combo pack, saving up to £20 compared to individual price
  • Supplied with 5x STELLA ARGB fans and AMBER5 controller
  • 366 Pre-Programmed RGB Modes
  • 21-key RF Remote Control Unit
  • ARGB Sync Compatible
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$42.89
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13 in stock

Noctua NF-A12x25 PWM chromax.black.swap 12V 2000RPM 120mm Fan

142 in stock
NF-A12x25 PWM chromax.black.swap 12V 2000RPM 120mm Fan
$31.62
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  • All black version of the award winning NF-A12x25 series
  • Impressive performance and low noise from 18.8 dB(A)
  • Manufactured from Sterrox liquid-crystal polymer compound
  • Ideally suited for any application
  • Improved SS02 bearings
  • Six year warranty
More Details
$31.62
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142 in stock

Noctua NF-F12 iPPC PWM 12V 2000RPM IP67 120mm High Performance Fan

40 on order. At present we do not have a delivery date from our supplier, but we are accepting back orders.
NF-F12 iPPC PWM 12V 2000RPM IP67 120mm High Performance Fan
$31.62
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  • Based on the award-winning NF-F12 design
  • 2000rpm PWM industrialPPC version
  • Three-phase motor design
  • Fibre-glass reinforced polyamide construction
  • Certified IP67 water and dust protection
  • Integrated Anti-Vibration Pads
  • Six year warranty
More Details
$31.62
Add to Basket
40 on order. At present we do not have a delivery date from our supplier, but we are accepting back orders.

Noctua NF-A12X25 5V 1900RPM 120mm Ultimate Quality Quiet Fan

10 in stock
NF-A12X25 5V 1900RPM 120mm Ultimate Quality Quiet Fan
$29.58
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  • Impressive performance and low noise from 18.8 dB(A)
  • 5V Version with USB power adapter
  • Manufactured from Sterrox liquid-crystal polymer compound
  • Ideally suited for any application
  • Improved SS02 bearings
  • Six year warranty
More Details
$29.58
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10 in stock

Noctua NF-A12x25r PWM 12V 2000RPM 120mm Round Frame Quiet Fan

22 in stock
NF-A12x25r PWM 12V 2000RPM 120mm Round Frame Quiet Fan
$29.58
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  • Impressive performance and low noise from 18.8 dB(A)
  • Round frame fan, non-standard holes spacing, 93x83 mm
  • Manufactured from Sterrox liquid-crystal polymer compound
  • Ideally suited for any application
  • Improved SS02 bearings
  • Six year warranty
More Details
$29.58
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22 in stock

Noctua NF-A12x25 ULN 12V 1200RPM 120mm Ultimate Quality Quiet Fan

52 in stock
NF-A12x25 ULN 12V 1200RPM 120mm Ultimate Quality Quiet Fan
$29.58
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  • Impressive performance and low noise from 7.6 dB(A)
  • Manufactured from Sterrox liquid-crystal polymer compound
  • Ideally suited for any application
  • Improved SS02 bearings
  • Six year warranty
More Details
$29.58
Add to Basket
52 in stock

Noctua NF-A12x25 PWM 12V 2000RPM 120mm Ultimate Quality Quiet Fan

50 in stock
NF-A12x25 PWM 12V 2000RPM 120mm Ultimate Quality Quiet Fan
$29.58
Add to Basket
  • Impressive performance and low noise from 18.8 dB(A)
  • Manufactured from Sterrox liquid-crystal polymer compound
  • Ideally suited for any application
  • Improved SS02 bearings
  • Six year warranty
More Details
$29.58
Add to Basket
50 in stock

Noctua NF-A12X25 LS-PWM 12V 1200RPM 120mm Ultimate Quality Quiet Fan

13 in stock
NF-A12X25 LS-PWM 12V 1200RPM 120mm Ultimate Quality Quiet Fan
$29.58
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  • Impressive performance and low noise from 18.8 dB(A)
  • Manufactured from Sterrox liquid-crystal polymer compound
  • Ideally suited for any application
  • Improved SS02 bearings
  • Six year warranty
More Details
$29.58
Add to Basket
13 in stock

Noctua NF-A12x25 FLX 12V 2000RPM 120mm Ultimate Quality Quiet Fan Ultra

15 in stock
NF-A12x25 FLX 12V 2000RPM 120mm Ultimate Quality Quiet Fan
$29.58
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  • Impressive performance and low noise from 14.2 dB(A)
  • Manufactured from Sterrox liquid-crystal polymer compound
  • Ideally suited for any application
  • Improved SS02 bearings
  • Six year warranty
More Details
$29.58
Add to Basket
15 in stock

Noctua NF-A12X25 PWM 5V 1900RPM 120mm Ultimate Quality Quiet Fan

340 in stock
NF-A12X25 PWM 5V 1900RPM 120mm Ultimate Quality Quiet Fan
$29.58
Add to Basket
  • Impressive performance and low noise from 18.8 dB(A)
  • 5V PWM Version with USB power adapter
  • Manufactured from Sterrox liquid-crystal polymer compound
  • Ideally suited for any application
  • Improved SS02 bearings
  • Six year warranty
More Details
$29.58
Add to Basket
340 in stock

Noctua NF-F12 iPPC PWM 12V 3000RPM 120mm High Performance Fan

65 in stock
NF-F12 iPPC PWM 12V 3000RPM 120mm High Performance Fan
$27.53
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  • Based on the award-winning NF-F12 design
  • 3000rpm PWM industrialPPC version
  • Three-phase motor design
  • Fibre-glass reinforced polyamide construction
  • Certified IP52 water and dust protection
  • Integrated Anti-Vibration Pads
  • Six year warranty
More Details
$27.53
Add to Basket
65 in stock

Noctua NF-F12 iPPC PWM 12V 2000RPM 120mm High Performance Fan

71 in stock
NF-F12 iPPC PWM 12V 2000RPM 120mm High Performance Fan
$27.53
Add to Basket
  • Based on the award-winning NF-F12 design
  • 2000rpm PWM industrialPPC version
  • Three-phase motor design
  • Fibre-glass reinforced polyamide construction
  • Certified IP52 water and dust protection
  • Integrated Anti-Vibration Pads
  • Six year warranty
More Details
$27.53
Add to Basket
71 in stock

Noctua NF-F12 iPPC 12V 2000RPM 120mm High Performance Fan

6 in stock
NF-F12 iPPC 12V 2000RPM 120mm High Performance Fan
$27.53
Add to Basket
  • Based on the award-winning NF-F12 design
  • 2000rpm industrialPPC version
  • Three-phase motor design
  • Fibre-glass reinforced polyamide construction
  • Certified IP52 water and dust protection
  • Integrated Anti-Vibration Pads
  • Six year warranty
More Details
$27.53
Add to Basket
6 in stock

Noctua NF-S12A PWM chromax.black.swap 12V 1200RPM 120mm Fan

70 in stock
NF-S12A PWM chromax.black.swap 12V 1200RPM 120mm Fan
$25.49
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  • Supplied with anti-vibration pads in six different colours
  • Advanced Acoustic Optimisation Frame Technology
  • S-Series Blade Geometry with Anti-Stall Knobs
  • Improved SS02 bearings
  • Six year warranty
More Details B-Grade available
$25.49
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70 in stock

Noctua NF-F12 PWM chromax.black.swap 12V 1500RPM 120mm Fan

Only 30 left in stock, 40 more overdue by 2 days
NF-F12 PWM chromax.black.swap 12V 1500RPM 120mm Fan
$25.49
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  • Supplied with anti-vibration pads in six different colours
  • Focused Flow Frame - for focused airflow
  • Varying Angular Distance and Vortex Control Notches
  • Improved SS02 bearings
  • Six year warranty
More Details B-Grade available
$25.49
Add to Basket
Only 30 left in stock, 40 more overdue by 2 days

Gelid Solutions Stella Frost Daisy Chain, 3x 120mm fans

8 in stock
Stella Frost Daisy Chain, 3x 120mm fans
$25.49
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  • Individually addressable RGB daisy-chain fans
  • Icy frame assembly and all-white colour
  • 24 ARGB LEDs per fan
  • Dual ring lighting
  • Airflow optimised impeller
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$25.49
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8 in stock

Noctua NF-A12x15 PWM chromax.black.swap 12V 1850RPM 120x15mm Fan

67 in stock
NF-A12x15 PWM chromax.black.swap 12V 1850RPM 120x15mm Fan
$24.47
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  • Award-winning Noctua quality in a 120mm x 15mm fan
  • chromax.black.swap version
  • Noctua’s AAO (Advanced Acoustic Optimisation)
  • Coloured integrated Anti-Vibration Pads
  • Six year warranty
  • 55.4 CFM, 23.9 dBA at 1850 RPM
More Details
$24.47
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67 in stock

Noctua NF-A12x15 FLX 12V 1850RPM 120x15mm Slim-line Fan

19 in stock
NF-A12x15 FLX 12V 1850RPM 120x15mm Slim-line Fan
$22.42
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  • Award-winning Noctua quality in a 120mm x 15mm fan
  • Noctua’s AAO (Advanced Acoustic Optimisation)
  • Integrated Anti-Vibration Pads
  • Six year warranty
  • From 41.7 CFM, 16.8 dBA at 1400 RPM
More Details
$22.42
Add to Basket
19 in stock

Noctua NF-A12x15 PWM 12V 1850RPM 120x15mm Slim-line Fan

93 in stock
NF-A12x15 PWM 12V 1850RPM 120x15mm Slim-line Fan
$22.42
Add to Basket
  • Award-winning Noctua quality in a 120mm x 15mm fan
  • Noctua’s AAO (Advanced Acoustic Optimisation)
  • Integrated Anti-Vibration Pads
  • Six year warranty
  • From 41.7 CFM, 16.8 dBA at 1400 RPM
More Details
$22.42
Add to Basket
93 in stock

Noctua NF-S12A PWM 12V 1200RPM 120mm Ultra Quiet Cooling Fan

7 in stock
NF-S12A PWM 12V 1200RPM 120mm Ultra Quiet Cooling Fan
$22.42
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  • Two speed settings for maximum quietness
  • High 62.21 CFM airflow
  • Advanced Acoustic Optimisation Frame
  • Custom NE-FD1 circuitry for smooth speed control
  • Smooth SSO-Bearings
  • Six year warranty
More Details
$22.42
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7 in stock

Noctua NF-F12 PWM 12V 1500RPM Focused Flow Cooling Fan

58 in stock
NF-F12 PWM 12V 1500RPM Focused Flow Cooling Fan
$22.42
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  • Noctua’s first PWM fan
  • Focused Flow Frame - for focused airflow
  • Varying Angular Distance and Vortex Control Notches
  • Improved SS02 bearings
  • Six year warranty
More Details
$22.42
Add to Basket
58 in stock

Noctua NF-F12 PWM 5V 1500RPM 120mm Focused Flow Cooling Fan

17 in stock
NF-F12 PWM 5V 1500RPM 120mm Focused Flow Cooling Fan
$22.42
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  • 5V 4-pin PWM version with USB power adapter
  • Focused Flow Frame - for focused airflow
  • Varying Angular Distance and Vortex Control Notches
  • Improved SS02 bearings
  • Six year warranty
More Details
$22.42
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17 in stock

Noctua NF-S12A ULN 12V 800RPM 120mm Ultra Low Noise Cooling Fan

26 in stock
NF-S12A ULN 12V 800RPM 120mm Ultra Low Noise Cooling Fan
$22.42
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  • Noise levels from only 6.7 dB(A)
  • High 43.73 CFM airflow
  • Advanced Acoustic Optimisation Frame
  • Two speed settings for maximum quietness
  • Smooth SSO-Bearings
  • Six year warranty
More Details
$22.42
Add to Basket
26 in stock

Noctua NF-S12A FLX 12V 1200RPM 120mm Flexible Ultra Quiet Cooling Fan

13 in stock
NF-S12A FLX 12V 1200RPM 120mm Flexible Ultra Quiet Cooling Fan
$22.42
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  • Noise levels from only 7.4 dB(A)
  • High 63.27 CFM airflow
  • Advanced Acoustic Optimisation Frame
  • Three speed settings for maximum quietness
  • Smooth SSO-Bearings
  • Six year warranty
More Details
$22.42
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13 in stock

Noctua NF-F12 5V 1500RPM 120mm Premium Grade Fan

17 in stock
NF-F12 5V 1500RPM 120mm Premium Grade Fan
$22.42
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  • 5V 3-pin version with USB power adapter
  • Focused Flow Frame - for focused airflow
  • Varying Angular Distance and Vortex Control Notches
  • Improved SS02 bearings
  • Six year warranty
More Details
$22.42
Add to Basket
17 in stock

be quiet Silent Wings 3 120mm PWM Quiet Fan, BL066

5 in stock
Silent Wings 3 120mm PWM Quiet Fan, BL066
$20.23
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  • Virtually inaudible operation at 16.4 dB(A) PWM fan
  • 6-pole fan motor with three phases giving less vibration
  • Advanced fluid-dynamic bearing (FDB) enables a long fan life
  • Seven fan blades with optimised surface structures ensure excellent airflow
  • The rubberised fan frame producing extremely high air pressure
  • Removable anti-vibration mountings minimise the transmission of vibrations
More Details B-Grade available
$20.23
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5 in stock

be quiet Silent Wings 3 120mm 3pin Quiet Fan, BL064

1 in stock
Silent Wings 3 120mm 3pin Quiet Fan, BL064
$19.71
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  • Virtually inaudible operation at 16.4 dB(A) 3pin fan
  • 6-pole fan motor with three phases giving less vibration
  • Advanced fluid-dynamic bearing (FDB) enables a long fan life
  • Seven fan blades with optimised surface structures ensure excellent airflow
  • The rubberised fan frame producing extremely high air pressure
  • Removable anti-vibration mountings minimise the transmission of vibrations
More Details
$19.71
Add to Basket
1 in stock

Noctua NF-P14r REDUX PWM 12V 1500RPM 120/140mm Quiet Case Fan

17 in stock
NF-P14r REDUX PWM 12V 1500RPM 120/140mm Quiet Case Fan
$16.29
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  • Proven NF-P14 PWM design
  • Streamlined redux edition
  • Round 140mm frame with 120mm mounting holes
  • Vortex-Control Notches
  • Custom designed PWM IC with SCD
  • Six year manufacturer’s warranty
More Details
$16.29
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17 in stock

Scythe Kaze Flex 120mm PWM RGB 1200RPM Case Fan

17 in stock
Kaze Flex 120mm PWM RGB 1200RPM Case Fan
$14.50
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  • Quiet PC PWM cooling fan
  • Closed Fluid Bearings
  • Eight RGB LEDs
  • 24.9 dB(A) / 1200 RPM / 51.2 CFM
  • MTBF 120,000 hours
More Details
$14.50
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17 in stock

Gelid Solutions Stella Infinity 120mm ARGB Fan New

38 in stock
Stella Infinity 120mm ARGB Fan
$13.28
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  • Dual ring RGB lighting with 24 separate LEDs
  • Airflow optimised
  • Hydro Dynamic Bearings
  • Wide PWM range - 500 to 1600 RPM
  • 35.0 dB(A) / 1600 RPM / 70.0 CFM
More Details
$13.28
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38 in stock

Noctua NF-S12B REDUX 12V 700RPM 120mm Quiet Case Fan

235 in stock
NF-S12B REDUX 12V 700RPM 120mm Quiet Case Fan
$13.23
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  • Proven NF-S12B design
  • Streamlined redux edition
  • Designed for efficient case ventilation
  • Smooth Commutation Drive 2
  • Six year warranty
More Details
$13.23
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235 in stock

Noctua NF-P12 REDUX PWM 12V 1700RPM 120mm Quiet Case Fan

Out of stock. At present we do not have a delivery date from our supplier, but we are accepting back orders.
NF-P12 REDUX PWM 12V 1700RPM 120mm Quiet Case Fan
$13.23
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  • 1700 RPM, 70.7 CFM at 25.1(A)
  • Pressure-optimised nine blade design
  • Vortex-control notches
  • Smooth commutation drive
  • SSO bearing
  • Six years warranty
More Details
$13.23
Add to Basket
Out of stock. At present we do not have a delivery date from our supplier, but we are accepting back orders.

Noctua NF-S12B REDUX PWM 12V 1200RPM 120mm Quiet Case Fan

44 in stock
NF-S12B REDUX PWM 12V 1200RPM 120mm Quiet Case Fan
$13.23
Add to Basket
  • Proven NF-S12B design
  • Streamlined redux edition
  • Designed for efficient case ventilation
  • Custom designed PWM IC with SCD
  • Six year warranty
More Details
$13.23
Add to Basket
44 in stock

Noctua NF-S12B REDUX 12V 1200RPM 120mm Quiet Case Fan

4 in stock
NF-S12B REDUX 12V 1200RPM 120mm Quiet Case Fan
$13.23
Add to Basket
  • Proven NF-S12B design
  • Streamlined redux edition
  • Designed for efficient case ventilation
  • Smooth Commutation Drive 2
  • Six year warranty
More Details
$13.23
Add to Basket
4 in stock

Noctua NF-P12 REDUX 12V 900RPM 120mm Quiet Case Fan

26 in stock
NF-P12 REDUX 12V 900RPM 120mm Quiet Case Fan
$13.23
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  • 900 RPM, 37.3 CFM at only 12.6 dB(A)
  • Pressure-optimised nine blade design
  • Vortex-control notches
  • Smooth commutation drive
  • SSO bearing
  • Six years warranty
More Details
$13.23
Add to Basket
26 in stock

Noctua NF-P12 REDUX PWM 12V 1300RPM 120mm Quiet Case Fan

2 days overdue, 10 pre-ordered
NF-P12 REDUX PWM 12V 1300RPM 120mm Quiet Case Fan
$13.23
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  • 1300 RPM, 54.3 CFM at only 19.8 dB(A)
  • Pressure-optimised nine blade design
  • Vortex-control notches
  • Smooth commutation drive
  • SSO bearing
  • Six years warranty
More Details
$13.23
Add to Basket
2 days overdue, 10 pre-ordered

Noctua NF-P12 REDUX 12V 1300RPM 120mm Quiet Case Fan

2 in stock
NF-P12 REDUX 12V 1300RPM 120mm Quiet Case Fan
$13.23
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  • 1300 RPM, 54.3 CFM at only 19.8 dB(A)
  • Pressure-optimised nine blade design
  • Vortex-control notches
  • Smooth commutation drive
  • SSO bearing
  • Six years warranty
More Details
$13.23
Add to Basket
2 in stock

Scythe Kaze Flex 120mm 3-pin RGB 1800 RPM Case Fan

4 in stock
Kaze Flex 120mm 3-pin RGB 1800 RPM Case Fan
$12.66
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  • Quiet PC 3-pin cooling fan
  • Closed Fluid Bearings
  • Eight RGB LEDs
  • 35.8 dB(A) / 1800 RPM / 79.8 CFM
  • MTBF 120,000 hours
More Details
$12.66
Add to Basket
4 in stock

Scythe Kaze Flex 120mm 3-pin RGB 1200 RPM Case Fan

26 in stock
Kaze Flex 120mm 3-pin RGB 1200 RPM Case Fan
$12.47
Add to Basket
  • Quiet PC cooling fan
  • Closed Fluid Bearings
  • Eight RGB LEDs
  • 24.9 dB(A) / 1200 RPM / 51.2 CFM
  • MTBF 120,000 hours
More Details
$12.47
Add to Basket
26 in stock

Gelid Solutions Stella 120mm Dual Ring ARGB Fan

60 in stock
Stella 120mm Dual Ring ARGB Fan
$12.25
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  • Dual ring RGB lighting
  • Airflow optimised
  • Double ball bearings
  • Wide PWM range - 500 to 1600 RPM
  • 35.0 dB(A) / 1600 RPM / 70.0 CFM
More Details
$12.25
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60 in stock

Gelid Solutions Radiant-D 120mm Extreme Performance Programmable Digital-RGB PWM Fan

68 in stock
Radiant-D 120mm Extreme Performance Programmable Digital-RGB PWM Fan
$11.95
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  • 9 Full Colour RGB LEDs
  • Programmable Digital-RGB Control
  • Extreme Static Pressure
  • High Precision Shark-Tooth Blade
  • Noiseless Motor Drive IC
  • Ultra-Durable Double Ball Bearing
  • CFM 77.2, 40.4 dBA Max, 500-2000 RPM
More Details
$11.95
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68 in stock

Gelid Solutions Slim 12 PL Blue, Silent Slim 120mm PWM Fan with LEDs

3 in stock
Slim 12 PL Blue, Silent Slim 120mm PWM Fan with LEDs
$10.42
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  • Hydro Dynamic bearings
  • PWM control
  • Blue LED lights with on/off switch
  • Very quiet operation
  • High airflow
  • Three year warranty
More Details
$10.42
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3 in stock

Gelid Solutions Silent 12 PWM Black, 120mm Quiet Case Fan

87 in stock
Silent 12 PWM Black, 120mm Quiet Case Fan
$10.11
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  • Silent Operation
  • Optimised Fan Blades
  • High Airflow and High Static Pressure
  • Long Lifetime
More Details
$10.11
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87 in stock

Gelid Solutions Silent 12 Black, 120mm Quiet Case Fan

80 in stock
Silent 12 Black, 120mm Quiet Case Fan
$8.27
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  • Silent Operation
  • Optimised Fan Blades
  • High Airflow and High Static Pressure
  • Long Lifetime
More Details
$8.27
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80 in stock

Gelid Solutions Silent 12, 120mm Quiet Case Fan

108 in stock
Silent 12, 120mm Quiet Case Fan
$8.27
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  • Silent Operation
  • Optimised Fan Blades
  • High Airflow and High Static Pressure
  • Rubber Fan Mounts
  • Long Lifetime
More Details
$8.27
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108 in stock

FAQ

  • How do I measure fan size?

    The size of fan you need will generally be determined by the size of the fan fitting position in your PC case. The sizes of all the fans on our website are shown as measured along any one of the fan’s four sides, NOT the distance between the fan’s screw holes! Our most popular fan size is 120mm, followed by 80mm. This isn’t really dictated by customer preference, but more by recent designs of PC cases.

    As for the thickness (depth) of the fan, generally 25mm (1 inch) is by far the most common depth, although smaller fans can have shallower depths such as 15mm or even 10mm. All our fans are 25mm thick unless otherwise stated. If you have any questions about which fan you should order, please don’t hesitate to get in touch.

    If you know the distance between the fan mounting screw holes but don’t know what fan size to order, please see the following table. Note that the mounting hole measurements shown below are taken horizontally or vertically between the holes and not diagonally.

    Screw hole spacings and fan sizes

    Space Between Screw Holes Fan Size
    32mm 40mm
    40mm 50mm
    50mm 60mm
    60mm 70mm
    72mm 80mm
    83mm 92mm
    105mm 120mm
  • I received a small cable (resistor) with my fan; what is it for?

    The resistor cable (also called Ultra Low Noise or ULN cable) is designed to allow the fan to run slightly slower for even quieter operation. The benefit in lower running noise is significant. Although the airflow will be reduced slightly, this usually has minimal effect on PC temperature. We would generally recommend using the ULN resistor cable for best results in almost all circumstances.

  • How can I tell which way the air blows through the fan?

    Hold the fan so that the round fan sticker is facing you. You are looking at the rear of the fan. When you plug the fan in, the air will be blowing towards you. If you want a fan to act as an air intake, then the fan sticker will be facing the inside of the case. Some fans also have two small arrows moulded into their plastic housing - one arrow shows the direction of airflow, and the other (at 90°) shows the direction of blade rotation.

  • Is it possible to use a 4-pin PWM fan or CPU cooler with a motherboard which has only 3-pin fan headers on it?

    Electrically, there is no problem doing this - the fourth pin on the fan cable is used purely for PWM control and is not needed in order for the fan to run. So you can plug the 4-pin fan connector onto the 3-pin motherboard fan header, leaving the fourth pin not connected to anything. The fan will potentially run at full speed, so if you would like to reduce the speed of the fan you will need to adjust the fan speed setting in your BIOS or use fan control software such as SpeedFan in Windows.

    The only other problem to consider is that occasionally, components immediately adjacent to the motherboard fan header can get in the way of the larger 4-pin fan connector, physically preventing connection. This problem also occurs if you try to use an in-line fan speed controller such as the one made by Gelid.

    Another avenue to explore is the possibility of using a bay-mounted fan controller. Several models are available now which provide 4-pin fan headers, so this is an easy way to use 4-pin PWM fans in a PC system which has only 3-pin fan headers on its motherboards. When using this method, you may find it necessary to disable any fan warning settings in your motherboard BIOS, since the motherboard may incorrectly believe that its CPU fan has failed when the fan is connected to a fan controller rather than directly to the motherboard itself.