Base measures 1-3/4 wide by 5 long, which allows for mounting on beams, joists or studs as narrow as 2 Two No. 8 wood screws are furnished to hold base on 3-3/16 centers Use with 2 or 3 wire, #12 or #14 nonmetallic sheathed cable Bus bars for feed-thru connections Knockouts for back wiring Brown phenolic body Medium base UL listed 600 watt 250 volt