The Horizontal 21 cu. in. PVC 1-Gang Wall Box Adjust-a-box with Adjustable Bracket for Horizontal Mount is designed to allow adjustment of depth after the wall covering has been installed. Adjusts to any wall covering. Designed to work with non-metallic sheathed cable in accordance with Article 314 of the NEC. Great for light commercial and residential applications, the box is crafted with non-conductive PVC for durability and is fire rated and UL listed to help ensure safety.