The NF-A9x14 PWM is a highly optimized, quiet fan of premium quality that utilizes cutting-edge aerodynamic design features such as Flow Acceleration Channels and Noctua's AAO frame system. With its slim profile, the NF-A9x14 is perfect for low-profile CPU coolers and any other applications that require thinner fans. Noctua's innovative PWM IC allows for fully automatic control, and the SSO2 reference-class bearing ensures superb smoothness and excellent long-term stability.