Electrical Box, Box Type Square, Number of Gangs 2, Bracket Type -, Capacity 21 cu in, Material Galvanized Zinc, Number of 1/2 In. Back Knockouts 4, Number of 1/2 In. Side Knockouts 12, Clamp Type -, Nominal Depth 1 1/2 in, Nominal Length 4 in, Nominal Width 4 in, Color Silver