Delta AFB1212SHE-PWM 120mm x 38mm 4pin PWM+Tac Sensor, Extreme Hi-speed 3700 RPM, 151 CFM Case Fan Delta AFB1212SHE-PWM 4pin PWM+Tac Sensor 120mm x 120mm x 38mm Extreme Hi-speed 3700 RPM, 151 CFM Case Fan