4 in. 21 Cu. In. Steel Pre-Galvanized Square Box Extension Ring

4 in. 21 Cu. In. Square Box Extension Ring

4 in. W X 1-1/2 in. D Steel Metallic Square Extension Ring With Six 1/2 in. KO's And Six CKO's (1-Pack)

4 in. H X 1-7/8 in. D Steel Metallic 1-Gang Welded Extention Ring With Eight 1/2 in. KO's, 1-Pack

4 in. 1-1/2 in. New Work Deep Pre-Galvanized Metal Octagon Electrical Box Extension Ring

4-11/16 in. 2-Gang New Work Square Metal Electrical Box Extension Ring

Steel City 531511234UB 4" X 1-1/2" Deep Square Box Extension Ring W/ 1/2" & 3/4" Eccentric Knockouts | Supplyhouse.Com

1-Gang Metal Weatherproof Electrical Outlet Box Extension Ring With (6) 3/4 Inch Holes, Gray

1-Gang Metal Weatherproof Electrical Outlet Box Extension Ring With (4) 1/2 Inch Holes, Gray

4 in W X 1-1/2 in. D Steel Metallic Octagon Extension Ring With Two 1/2 in. KO's And Two 3/4 in. KO's

Arlington BE4 4-Gang Electrical Outlet Box Extender (White) | Supplyhouse.Com

1-Gang Metal Electrical Switch Box Extension

4-Gang Metal Electrical Box With 1/2 in. Knockouts And CV Bracket

1-Gang 3/4 in. Electrical Receptacle Box Extension Ring 5-Pack

4 in. W X 1-1/2 in. D Drawn Octagon Extension Ring With Two 1/2 in. And Two 3/4 in. Knockouts, 1-Pack

2-1/2 in. D Steel Metallic 4-Gang Welded Switch Box With Fourteen 1/2 in. And Fourteen 3/4 in. KO's, 1-Pack

Smart Box 4-Gang Adjustable Depth Device Box