The Steel City 531711234 is a new, welded 4-inch square box extension ring designed to increase the capacity of existing outlet boxes. It is constructed from pre-galvanized steel, ensuring durability and resistance to corrosion. With a depth of 2-1/8 inches and a total capacity of 30.3 cubic inches, it provides ample space for additional wiring or devices. The extension ring features 12 knockouts, including six 1/2-inch and six 1/2-inch/3/4-inch eccentric knockouts, allowing for flexible conduit entry. It is UL Listed, meeting recognized safety and performance standards. This extension ring is ideal for both commercial and residential electrical installations requiring extra box depth.