Arctic Cooling, Case Fan ARCTIC F12 Pro PWM, Patented PWM Sharing Technology (PST), Dimensions: 120 L x 120 W x 34 H mm, Rated Fan Speed: 400 - 1500 RPM (controlled by PWM), Air Flow: 57 CFM / 96.8 m3/h, Noise Level: 0.5 Sone, Fluid Dynamic Bearing, PWM amplifier integrated on motor circuit, 4 pin plug for receiving power and PWM signal from motherboard, 4 pin socket for CPU cooler or second fan, 3 pin plug to send fan RPM signal to motherboard