Single Gang, Horizontal Adjust-A-Box, Allows Installer To Adjust Box To Any Thickness From 0 To 1-3/4" After Installation, Comes Preset At 1/2", 21CUIN Capacity, To Install Simply Clip Included Bracket Onto Stud, Turning The Screw Adjust Box In Or Out To Make It Flush With Any Wall Covering, UL Listed.