Electrical Box, Box Type Octagon, Number of Gangs 2, Bracket Type -, Capacity 21.5 cu in, Material Galvanized Steel, Number of 1/2 In. Back Knockouts 1, Number of 1/2 In. Side Knockouts 2, Clamp Type (4) NM-B, Nominal Depth 2 1/8 in, Nominal Length 4 in, Nominal Width 4 in, Color Silver, Standards File E195978, UL 514-A Listed