The LBS4-R includes clips for mounting a 4” (EIA 5”) speaker with screw mount grille model WB-4 and no backbox. As with all projects, speaker installation should be performed per local building codes and regulations, many of which require a backbox for speaker installation. The LBS4-series is engineered to distribute the speaker assembly weight to the ceiling support system in a suspended 2' x 2' or 2' x 4' tile ceiling system. It is galvanized 20-gauge steel (23.75"L x 12.125"W) with a round center opening.