NF-A4X20 PWM Featuring advanced aerodynamic design measures such as Flow Acceleration Channels and Noctua’s AAO frame, the NF-A4x20 is a highly optimised, premium-quality quiet fan in size 40x20mm. The PWM version sports Noctua’s custom-designed NE-FD1 IC for fully automatic speed control via 4-pin fan headers and comes with a Low-Noise Adaptor as well as an OmniJoin™ Adaptor Set for easy connection to proprietary fan headers. Its superb running smoothness, reference-class SSO2 bearing and Noctua’s trusted premium quality make it an elite choice for the highest demands. Specifications: Size 40x40x20 mm Mounting hole spacing 32x32 mm Connector & pin-configuration 4-pin PWM Cable length 20cm + 30cm NA-EC1 extension cable Bearing SSO2 Blade geometry A-Series with Flow Acceleration Channels Frame technology AAO (Advanced Acoustic Optimisation) Rotational speed (+/- 10%) 5000 RPM Rotational speed with L.N.A. (+/- 10%) 4400 RPM Min. rotational speed (PWM, +/-20%) 1200 RPM Airflow 9,4 m³/h Airflow with L.N.A. 8,3 m³/h Acoustical noise 14,9 dB(A) Acoustical noise with L.N.A. 12,2 dB(A) Static pressure 2,26 mm H₂O Static pressure with L.N.A. 1,75 mm H₂O Max. input power 0,6 W Max. input current 0,05 A Operating voltage 12 V Voltage PWM signal 5 V MTTF > 150.000 h Scope of delivery Low-Noise Adaptor (L.N.A.) 4-pin y-cable 30cm extension cable OmniJoin™ adaptor set NA-AV3 anti-vibration mounts Fan screws Warranty 6 years