Noctua NF-A4x10 FLX 40mm Blæser

Noctua NF-A4x10 FLX 40mm. Featuring advanced aerodynamic design measures such as Flow Acceleration Channels and Noctua’s AAO frame, the NF-A4x10 FLX is a highly optimised, premium quality quiet fan in 40x10mm size.
Flow Acceleration Channels.
The NF-A4x10 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
Reduced Motor Hub Size.
Thanks to its streamlined, compact motor design, the NF-A4x10’s motor hub is smaller than with conventional 4cm fans. This allows for more blade surface area and thus contributes to the NF-A4x10’s superior airflow and pressure performance.
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
Stepped Inlet Design.
Noctua’s Stepped Inlet Design adds turbulence to the influx in order to facilitate the transition from laminar flow to turbulent flow, which reduces tonal intake noise, improves flow attachment and increases suction capacity, especially in space restricted environments.
Inner Surface Microstructures.
With the tips of the fan blades ploughing through the boundary layer created by the Inner Surface Microstructures, flow separation from the suction side of the blades is significantly suppressed, which results in reduced blade passing noise and improved airflow and pressure efficiency.
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. 
Smooth Commutation Drive 2.
The latest version of Noctua’s advanced Smooth Commutation Drive system ensures superb running smoothness by eliminating torque variations and switching noises. This makes the NF-A4x10 remarkably quiet even at very close distance.
SSO2 Bearing.
The NF-A4x10 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.
Low-Noise Adaptor for full flexibility.
The NF-A4x10 FLX (Flexibility) is supplied with a Low-Noise Adaptor (L.N.A.) that reduces the maximum fan speed from 4500 to 3700rpm so that it can be fine-tuned for superior airflow or maximum quietness.
3 to 2-pin Adaptor and Polarity Protection.
The NF-A4x10 comes with an adaptor from 3-pin Molex to the 2-pin connectors used on many graphics cards or network and storage devices. An integrated diode provides polarity protection on 2-pin connections.
OmniJoin Adaptor Set.
Many devices featuring 40mm fans use proprietary fan headers, so the NF-A4x10 comes with Noctua’s OmniJoin Adaptor Set. Just cut the original fan’s cable, fix it to the adaptor using the supplied 3M Scotchlok™ connectors and you can plug the NF-A4x10 to proprietary fan headers!
Extensive Cabling Options.
The fan’s short 20cm primary cable minimises cable clutter in typical applications while the supplied 30cm extension provides extended reach when necessary. Both cables are fully sleeved.
6 years manufacturer’s warranty.
Noctua fans are renowned for their impeccable quality and outstanding longevity. Like all Noctua fans, the NF-A4x10 features an MTBF of more than 150.000 hours rating and comes with a full 6 years manufacturer’s warranty.