Enhance the capacity of your existing 4 square electrical boxes with this heavy-duty galvanized steel extension ring. Designed for new work, it provides the extra depth needed for complex wiring, larger devices, or to meet code-mandated wire fill requirements. Easily mount it directly onto the original box with screws for a secure and reliable installation in residential, commercial, or industrial settings.This 4 square extension ring is constructed from galvanized steel and offers a depth of 2-1/8. It is designed to extend the capacity of standard 4 square electrical boxes, accommodating complex wiring, larger devices, or code-mandated wire fill. It features 16 knockouts (10 x 1/2 and 6 x 3/4) and has a capacity of 491 ml. The product is intended for new work applications and is assembled.