Southwire Drawn 4 In. x 4 In. Square Box Extension is designed to increase the wiring capacity of junction boxes by adding 4-inch square extension rings. This product allows for additional conduit runs and electrical wiring without the need to remove existing conduit boxes and wiring from circuits, making upgrades and expansions easier and more efficient. It is both UL and RoHS compliant, ensuring safety and environmental standards are met. Model Number: 53151-S-UPC