The ARCTIC F PWM forward the PWM signal from the CPU to the whole case ventilation system. The entire system is cooled quietly, but still offers the superb performance when needed. Noise Level F8 : 0.3 SoneF9: 0.4 SoneF12: 0.3 Sone Min. Fan Speed F8 : 700 RPMF9: 600 RPMF12: 400 RPM Max. Fan Speed F8 : 2000 RPMF9: 1800 RPMF12: 1350 RPM Airflow F8 : 31 CFM / 52.7 m3/hF9 : 43 CFM / 73.1 m3/hF12 : 74 CFM / 125.7 m3/h Bearing Fluid Dynamic Bearing Dimensions (Packaging) F8 : 82 L x 82 W x 25 H mmF9: 95 L x 95 W x 26 H mmF12: 123 L x 123 W x 26 H mm Dimensions (Product) F8 : 80 mmF9: 92 mmF12: 120 mm Limited Warranty 6 years UPC F8 : 0872767002630F9: 0872767002647F12: 0872767002654 Net Weight F8 : 96 gF9: 110 gF12: 144 g itemnumber AFACO-080P0-GBA01.01.1 UPC Gross Weight 0.15 kg