Delta TFB0412EHN-PWM 40x28mm-4pin PWM, Extreme Hi-speed 15,000 RPM, 26cfm.
PWM fan connector you can let your motherboard keep this fan running at minimal speeds and still have the high end for those times when you really need it.
The Evercool 40mm x 28mm High Speed PWM Fan mounts on standard 40mm fan holes. This fan puts out a large volume of air for it's size. This fan uses energy saving PWM, and has a 4-pin PWM connector type.
Sunon PMD1204PQB1-PWM 40x28mm-4pin with PWM, Hi-speed.
With the PWM fan connector you can let your motherboard keep this fan running at minimal speeds and still have the high end for those times when you really need it.