Improve ventilation and allow more light to enter areas below deck. For installation only on wheel houses and cockpit canopies. Not suitable for use on normal decks and coachroof applications. The Pilot Hatch cannot be operated from the outside. Overall dimension for the hatch frame is 22 7/8"L 22 3/4"W. Cutout required is 20"L x 20"W. Tracks extend 14 11/16" beyond hatch frame edge. Hatch weighs 7.5lb. Lens is 10mm smoked gray acrylic.