This hatch can be used for a variety of applications. It is constructed with no back and a 1-1/8" collar. Made of a durable plastic that is UV resistant for a long life and resists fading, discoloring, and wear caused by road salts and acids. Can be painted to match any exterior with no preparation. Cut out dimension: 6-7/8" H x 6-3/8" W. Outside dimension: 8-1/2" H x 8" W. Polar White. Key Lock.