An optional back box (DP38BXFS) is available surface mount.F-Series Door Station Kit - Fon DP38BKFManufactured in aluminum with anodized Brass, Black, Bronze, and Aluminum finishesMounts into any standard double-gang masonry box as a flush mountOptional surface mount back box (DP38BXFS) mounts easily on almost any surfaces including fences and gatesAll back boxes are manufactured in steel with bla