FeaturesSingle and double-gang metallic outlet and switch boxes are acceptable for use in two-hour fire rated wallsBoxes with concentric or eccentric knockouts are suitable for bonding without any additional bonding means where used in circuits above or below 250 VACAll concentric or eccentric knockouts are 1/2 to 3/4 in combinations(6) 1/2 in side, (2) 1/2 in end knockout0.0625 in THKFor use 4 x 2-1/8 in handy boxProvided with flat ground tapped hole