ADA-compliant Caddy Model FMBS18 positions center of electrical boxes 18.5 in. above floor mounting surface. Box support allows for mounting of 4 in. or 4-11/16 in. U.S. or Canadian boxes, 1-1/2 in. or 2-1/8 in. deep. Unit can be mounted inside using tabs, or under floor track, independent of wall stud location. Built-in far side back support for 2-1/2 in., 3-1/2 in., and 4 in. metal/wood studs eliminates stocking of different size brackets.