UV-Resistant polycarbonate back, see-through cover and pre-mounted gasket protect devices inside from rain, sleet and snow without cracking or breaking. Non-corrosive and non-conductive. Snap-in inserts provide flexibility. Meets and exceeds UL outdoor low voltage landscape lighting requirements. Meets 1999 NEC Article 210-60 (b) for hotels and motels requiring covered receptacles behind beds and 2002 NEC Article 406.8 (B) (1) for receptacles in damp or wet locations. Comes standard with three inserts (for a total of 16 different configurations) - GFCI, duplex/toggle and toggle/four round in these sizes: 1-1/4 in (31-3/4 mm), 1-3/8 in (34.925 mm), 1-1/16 in (41.275 mm) and 1-3/4 in (44.45 mm). 3-1/4 in D x 6.445 in x 5.575 in.