Featuring advanced aerodynamic design measures such as Flow Acceleration Channels and Noctuas AAO frame, the NF-A6x25 is a highly optimised, premium quality quiet fan in 60x25mm size. The PWM version sports Noctuas custom designed NE-FD1 IC for fully automatic speed control via 4-pin fan headers and comes with a Low-Noise-Adaptor to reduce the maximum speed during PWM control from 3000 to 2100rpm. Its superb running smoothness, SSO2 bearing and Noctuas trusted premium quality make it an elite choice for the highest demands.