4 Square Blank Extension Ring 1-1/2 in. Deep no Knockout

These 4 in Square 1-1/2 in Deep Extension Rings have blank sides and an open back with mounting slots so they can be quickly and easily attached to existing 4 in Square boxes that require extra space for additional wires cables connectors or devices being installed inside the junction box. These extension rings are made from rugged galvanized steel and the blank sides are great for high security and vandal prone areas. They can also be customized with any knockout combination you require!