The BP-300 is 18-gauge steel with two cutouts (one for speaker, one for clock). It includes hardware and provisions for installing universal clock-mounting bracket for horizontal or vertical orientation. The speaker cutout has welded studs for installing an 8-inch speaker and mounted round grille with trim-ring bezel. The assembly will install to recessed backbox Model PC312 (ordered separately) using hinges and screws for easy service access with security. Overall dimensions of grille are 27.25"L x 17"W. White powder epoxy finish.