This back box is not removed when installing the NXD into a CB-TP12 Rough-In Box. The back box is only removed to gain access for the replacement of the Compact Flash component or upgrade to the VESA housing. The CB-TP12 Rough-In Boxes are optional metallic boxes that are secured onto stud beams prior to the installation of a solid surface. Installation procedures and configurations can vary. Specifications WARNING: INSTALLER, LEAVE A GAP BETWEEN THE STUD AND ROUGHIN BOX TO ACCOMMODATE THE DRYWA