The startechcom 8cm x 8cm x 25cm 3 18 x 3 18 x 1 dual ball bearing pc case fan is an add in cooling fan designed to fit most computers it can be used to circulate cool air into the case or exhaust warm air out preventing problems due to overheating components a quiet running brushless ball bearing dc motor coupled with a high efficiency blade design is capable of moving 37 cfm cubic feet per minute of air power is supplied to the fan using a power tap that is connected to the large l