Extension Ring Box Type Square Number of Gangs 2 Bracket Type - Capacity 29.5 cu in Material Galvanized Steel Number of 1/2 in Back Knockouts 0 Number of 1/2 in Side Knockouts 8 Clamp Type - Number of 3/4 in Side Knockouts 4 Nominal Depth 1 1/2 in Nominal Length 4 11/16 in Nominal Width 4 11/16 in Color Silver Standards CSA UL