This backbox on installations where the space behind the drywall is open, requiring a deep enclosure. This typically occurs in ceiling installations in which there is an air gap or large, unenclosed area behind the speaker. This product is also useful on installations where sound transfer from one floor to the next is of concern.This backbox is constructed of MDF and shipped disassembled. Assembly is simple and should take only 5 to 10 minutes with the aid of a power screwdriver. The parts are predrilled and the screws are included. A terminal cup with speaker wire pigtails allow the backbox to be completely assembled and attached to the speaker before the speaker is installed. Fiberglass insulation for the interior of the box is included.