Patented PWM Sharing Technology (PST) Best noise-performance ratio Patented fan holder eliminates the buzzing sounds Patented vibration absorption Fluid dynamic bearing extends service life Compatible with screwless mounting PST: 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 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 Weight: 140 g Bearing: Fluid Dynamic Bearing