4" square box 4 inches height x 4 inches width x 1-1/2 inches depth 21 cubic inches Concentric knockouts. Wraparound bracket for 2-1/2 inches and 3-5/8 inches steel studs. With integral support bracket. Raised ground screw. Volta VMB-30195

VMB-30195 - Shallow Square Steel Stud Junction Box With Knockouts (52151-KSSX)