The NF-A15 is a premium quality quiet 140mm fan with a round frame that complies with Noctua’s AAO (Advanced Acoustic Optimisation) standard. The NF-A15’s frame features 120mm mounting holes (105mm spacing) and has been enlarged to 150mm width in order to provide superior performance on today’s high-end CPU coolers. Featuring sophisticated aerodynamic design measures such as Flow Acceleration Channels, the NF-A15 further improves the renowned quiet cooling performance of the award-winning NF-P14. Noctua’s custom designed PWM IC for fully automatic speed control and reference class SSO2 bearings guarantee superb running smoothness and excellent long-term stability. Topped off with modular cabling, a Low-Noise Adaptor and 6 years manufacturer’s warranty, the NF-A15 is a premium choice for the highest demands.Succeeding the award-winning NF-P14Noctua's NF-P14 fan has become a default-choice among PC enthusiasts looking for a premium quality quiet 140mm fan. Thanks to its thoroughgoing aerodynamic optimisations, the NF-A15/14 provides higher static pressure and an even better airflow/noise ratio than its much acclaimed predecessor.Round 140mm frame with 150mm widthThe NF-A15 is tailor-made for use on today's high-end CPU coolers: While its 150mm width matches those of most high-end heatsinks, its 140mm height doesn't make it extend on top and thus ensures best case compatibility. The NF-A15's standard 120mm mounting holes (105mm spacing) also make it an ideal performance upgrade for 120mm case or CPU fans.Flow Acceleration ChannelsThe NF-A15 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.SSO2 BearingThe NF-A15 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.Metal bearing shellIn order to guarantee the highest possible degree of manufacturing precision, minimum tolerance and excellent long-term stability, the NF-A15 sports a CNC milled bearing shell made entirely from brass.Custom-designed PWM IC with SCDSupporting fully automatic PWM speed control, the NF-A15 PWM uses Noctua's novel, custom-designed NE-FD1 PWM IC that integrates Smooth Commutation Drive (SCD) technology. By providing smoother torque impulses, SCD suppresses PWM switching noises and thus makes the fan quieter at low speeds.Stops at 0% PWMWhen the fan is set to 0% PWM duty cycle by the motherboard or PWM fan controller, it will stop. This makes it ideal for creating setups with semi-passive cooling that automatically turn the fans off and thus run completely silent at idle if thermals allow.Low-Noise AdaptorThe NF-A15 PWM is supplied with a (L.N.A.) that reduces the maximum fan speed from 1200 to 900rpm. The L.N.A. can be used either to run the fan at a fixed speed of 900rpm 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 NF-A15 PWM fan to the same PWM fan header for automatic control.Ultra-Low Power ConsumptionDespite of its further improved performance, the NF-A15 PWM consumes only 0.96W of power, which amounts to a reduction of about 20% as compared to its predecessor. This doesn't only make it eco-friendly but also helps to cut down the electricity bill!6-year manufacturer’s warrantyNoctua fans are renowned for their impeccable quality and outstanding longevity. Like all Noctua fans, the NF-A15 features an MTTF of more than 150.000 hours rating and comes with a full 6-year manufacturer's warranty.