C2G/Cables to Go 27077 3-Pin Fan to 4-Pin Power Adapter Cable (6 Inch) Convert a 3-pin fan connector to a standard 4-pin power connector Connector 1: (1) 3-pin Fan (Internal) Male Connector 2: (1) 4-pin Fan Male Lifetime Warranty For CPU and case fans, this adapter converts a 3-pin fan connector to a standard 4-pin power connector.