56 Welded concrete ring is suitable to use with masonry box. It features 0.062-Inch steel construction and has pre-galvanized finish. Square ring with four knockouts, has 3/4-Inch and 1-Inch double row knockout. It measures 4-Inch x 4-Inch x 4-Inch. Flat sides offer excellent contact for locknuts. Concrete ring is UL listed and CSA certified.