The DoorBell Fon Back Box (2-Gang Masonry Box Surface Mount) is used to mount any double-gang (F-Series) Door Station. This surface mount box allows you to mount the Door Station on a wall, fence, gate, or other entryway. The Back Box features black powder coating and an overhang for extra protection. Dimensions: 4.625 x 4.625 x 1.5625 inches. NOTE: Door Station not included.