12 Packs Square Extension Ring, 4" L X 4" W Electrical Box Extension Ring with 1/2" and 3/4" Knockouts, 1-1/2'' Deep, Electrical Box Extender, Galvanized$$Tools & Hardware Other

Knockouts: This electrical box extension ring is designed for multiple purposes with eight 1/2 inch knockouts and four 3/4 inch knockouts. Quality: This square extension ring is made of iron to ensure, effectively prevent rusting. Dimension: The capacity of this 4-inch square electrical box extender is 21.0 cubic inches. It is 4 inches square and has a depth of 1-1/2 inches. The trade size of the box is 2-gang, and a single toggle switch cover can only accommodate 1-gang. Application: This 4 inch square extension ring is designed to enclose wire connections, sockets, or switches. Ideal choice for exposing working applications. Package Include: 12 * 4" Square Extension Ring.