The MULTIFAN S7 is a quiet dual 120mm USB cooling fan designed for use in receiver DVR computer cabinets. It is manufactured by AC Infinity and comes with a 2-year manufacturer warranty. The fan operates at a maximum speed of 1300 rpm and has a maximum airflow volume of 52 CFM. It is made of plastic and has a dual ball bearing type. The voltage required for the fan to operate is between 3 to 7V DC.