The RV PRO Straight Blade Recessed receptacle is an industrial grade, grounded, side-wired, steel strap, Black (30 Amp) receptacle. It fits all wall plates with a 2.15" diameter center hole and offers the marked terminal for easy identification and quick wiring. The flush mount devices are suitable for single or double outlet boxes and the easy to wire terminals accept conductors up to 4 AWG30 A, 125 V, NEMA TT-30R, 2P, 3W.