Thanks to the Noctua AAO (Advanced Acoustic Optimization) frame system and advanced aerodynamic design features such as Flow Acceleration Channels, the NF-A9 offers even better silent cooling performance compared to the multiple award-winning NF-B9. The PWM version is equipped with Noctua's custom-designed NE-FD1 IC for fully automatic speed control and comes with a Low-Noise Adapter that reduces the maximum speed from 2000 to 1550 RPM. Its superb smooth operation, the ssO2 reference-class bearing, and Noctua's proven premium quality make the NF-A9 PWM a top solution for the highest demands.