SE1275 is formed from 20-gauge steel, measures 12.75"sq x 4"D. The rear features a universal hole pattern for installation to a 4" square, 4" octagon, 2-gang, or 1-gang E.O. box. The rear also includes a 3/8" hole with grommet for wire access. Additionally, a fire-retardant foam pad is applied on the inside (top rear) to help absorb speaker resonance. White powder epoxy finish.