This is designed for all 140mm fan installing in most PC cases that come with 120mm fan screw holes only. This will eliminate the unnecessary drilling on the chassis for 140mm fan. The Fan Adapter funnel design will channel airflow through the 120mm ventilation hole on the chassis. Fan adapter 140mm is design to mount a 140mm fan to a 120mm pre-drill hole on the computer case. Or it can be used on a 120mm fan to mount on a 140mm pre-drill holes on the computer case.