the fan1156pwm cpu cooler with pwm cooling fan for socket lga1156/1155 systems provides reliable and efficient cooling for compatible intel core i3/i5/i7 cpus. with pulse width modulation (pwm) technology, the fan speed can be dynamically controlled by the motherboard, so the fan runs at a speed that suits the operating conditions - lowering power consumption and fan noise when the system is idle, and delivering maximum cooling under full load conditions. air flow rate 65.61 (max) cfm connector type(s) 1 - molex fan (4 pin pwm) female fan bearing type ever lubricate bearing fan dimensions 95mm x 95mm x 25mm