Noctua NF-A4x20 FLX Premium 40mm Computer Case Fan - Ultra Quiet 3700/4400/5000 RPM Cooling Fan for PC, CPU, GPU, NAS & Small Form Factor Builds - Perfect for Gaming Rigs, Home Servers & HTPC Systems

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 FLX version provides 5000/4400/3700rpm speed settings via the supplied Low-Noise Adaptors and includes the 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. 40x20mm size Compared to Noctua’s award-winning NF-A4x10, the NF-A4x20 is twice as thick, which allows for increased static pressure performance and makes the NF-A4x20 ideal for demanding applications with high flow resistance. Flow Acceleration Channels The NF-A4x20 impeller features suction side Flow Acceleration Channels. By speeding up the airflow at the crucial outer blade regions, this measure reduces suction side flow separation and thus leads to better efficiency and lower vortex noise. SSO2 Bearing The NF-A4x20 features the further optimised second generation of Noctua's renowned, time-tested SSO bearing. With SSO2, the rear magnet is placed closer to the axis to provide even better stabilisation, precision and durability. Integrated Anti-Vibration Pads Integrated Anti-Vibration Pads made from extra-soft silicone minimise the transmission of minute vibrations while maintaining full compatibility with all standard mounting systems and fan clips used on heatsinks. Scope of delivery NA-RC10 Low-Noise Adaptor (L.N.A)NA-RC12 Ultra-Low-Noise Adaptor (U.L.N.A)NA-EC2 30cm extension cableOmniJoin adaptor set4x NA-AV3 anti-vibration mountsFan screws AAO frame Noctua's AAO (Advanced Acoustic Optimisation) frames feature integrated anti-vibration pads as well as Noctua's proprietary Stepped Inlet Design and Inner Surface Microstructures, both of which further refine the fan's performance/noise efficiency. NF-A4x20 PWM NF-A4x20 FLX NF-A4x20 5V PWM NF-A4x20 5V Add to Cart Add to Cart Buying Options Add to Cart Customer Reviews 4.8 out of 5 stars 1,844 4.8 out of 5 stars 2,401 4.8 out of 5 stars 3,398 4.8 out of 5 stars 369 Price $14.95$14.95 $14.95$14.95 — no data $14.95$14.95 Connector 4-pin PWM 3-pin 4-pin PWM 3-pin Voltage 12V 12V 5V 5V RPM Max: 5000 / Min: 1200 5000 Max: 5000 / Min: 1100 5000 RPM with L.N.A. 4400 4400 - no data - no data RPM with U.L.N.A. - no data 3700 - no data - no data Acoustical Noise 14,9 dB(A) 14,9 dB(A) 14,9 dB(A) 14,9 dB(A) Acoustical Noise with L.N.A. 12,2 dB(A) 12,2 dB(A) - no data - no data Acoustical Noise with U.L.N.A. - no data 8,5 dB(A) - no data - no data Size 40x40x20 mm 40x40x20 mm 40x40x20 mm 40x40x20 mm Colour Brown & Beige Brown & Beige Brown & Beige Brown & Beige