All Stealth speakers require a box enclosure to operate properly. This box is intended to be used where the space behind a Stealth speaker panel is open, or where a metal enclosure behind the speaker is required. Measuring 3.5" deep, this back boxes fit into standard 2x4 stud bays or larger apertures and are designed to fit in between 16"on-center studs. The MBX back boxe may be used in either walls or ceilings.Constructed of 1.1mm thick metal, the UL listed MBX back boxe is shipped fully assembled. Convenient knockouts for conduit are provided. The knockouts accept either 1/2" or 3/4" conduits and loom clamps. Each back box comes with insulation to improve sound quality. If additional sound isolation is required, Stealth offers accessory sound isolation kits to reduce rear-side sound leakage into adjacent spaces.