The NF-A20 is a highly optimised, premium quality quiet 200mm fan. Featuring an AAO (Advanced Acoustic Optimisation) standard frame as well as sophisticated aerodynamic design measures such as Flow Acceleration Channels, the NF-A20 brings the renowned quiet cooling performance of Noctuas award-winning A-series to the increasingly popular 20cm form factor. The FLX version provides 800/550rpm speed settings via the supplied Low-Noise Adaptor in order to provide full flexibility in fine-tuning the fan for maximum ventilation performance or near-silent operation. Its superb running smoothness, reference-class SSO2 bearing and Noctuas trusted premium quality make the NF-A20 an elite choice for the highest demands.Award-winning Noctua quality in 20cm sizeWhile more and more PC cases support 20cm intake, side-panel or exhaust fans, many of the bundled stock units and available aftermarket options are of questionable quality. By contrast, the NF-A20 is a true premium grade solution worthy of Noctuas award-winning A-series.154mm, 110x180mm and 170mm hole spacingIn order to ensure broad compatibility with todays PC cases, the NF-A20 features three sets of mounting holes: While the 154x154mm and 110x180mm spacing allow it to replace most 200mm fans, the 170x170mm spacing is used by many 230 and 250mm fans, which can thus also be replaced by the NF-A20.*Flow Acceleration ChannelsThe NF-A20 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.AAO FrameNoctua\'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 DesignNoctua\'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 MicrostructuresWith 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 padsIntegrated anti-vibration pads made from extra-soft silicone minimise the transmission of minute vibrations while maintaining full compatibility with all standard screws and other mounting systems.Smooth Commutation Drive 2The latest version of Noctua\'s advanced Smooth Commutation Drive system ensures superb running smoothness by eliminating torque variations and switching noises. This makes the fan remarkably quiet even at very close distances.Low-Noise AdaptorThe NF-A20 PWM is supplied with a (L.N.A.) that reduces the maximum fan speed from 800 to 550rpm. The L.N.A. can be used either to run the fan at a fixed speed of 550rpm or to cap the maximum speed when using automatic PWM control.Extensive cabling optionsThe 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 and a 4-pin y-cable allows the connection of a second fan to the same PWM fan header for automatic control.SSO2 bearingThe NF-A20 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.6-year manufacturers warrantyNoctua fans are renowned for their impeccable quality and outstanding longevity. Like all Noctua fans, the NF-A20 features an MTTF of more than 150.000 hours rating and comes with a full 6-year manufacturers warranty.Specifaction:- Size: 200x200x30 mm- Mounting hole spacing: 154x154, 110x180, 170x170 mm- Connector: 3-Pin- Bearing: SSO2- Blade Geometry: A-Series with Flow Acceleration Channels- Frame Technology: AAO (Advanced Acoustic Optimisation)- Rotational Speed: (+/- 10%) 800 RPM- Rotational Speed with L.N.A:. (+/- 10%) 550 RPM- Min. Rotational Speed: (PWM, +/-20%) 350 RPM- Airflow: 146,9 m/h- Airflow with L.N.A.: 1