The AP-300 grille is formed from single piece of 18-gauge steel and has full-perforation face and integral frame border. The subplate features cutout for standard 12-inch analog clock (by others) on one side and cutout for an 8-inch speaker (ordered separately) on the other. It includes provisions and hardware to attach the universal mounting bracket (for the clock) in horizontal or vertical orientation. The subplate features welded studs to install an 8-inch speaker. The subplate mounts to the grille (after bracket and speaker installation) using four screws. The grille/subplate assembly then mounts to surface backbox model PC712 (ordered separately) using hinges and screws for easy service access with security. Grille dimensions are 27.25"L x 17"W. The subplate is finished in black powder epoxy and grille is finished in white powder epoxy.