Five Oceans Marine Access Hatch with Lock 15 11/16" x 12 7/8" and 23 1/2&rdquo; x 13 5/18&rdquo; HIGH IMPACT MATERIAL which withstand rough weather conductions UV Stabilized Polypropylene HINGES SYSTEM that locks at 180 degree LOCKING Slam Latches NON SKID SURFACE on a Off-White Color REINFORCED LID with rubber seal Color: OFF-WHITE Cutout measures: 20 1/4 (516 mm) x 10 1/2 (268 mm) (Additional 5/8 with hatch hinges) Inside measures: 18 7/8 (479 mm) x 9 1/8 (231 mm) Outside measures: 23 1/2 (596 mm) x 13 5/8 (348 mm) Mounting Hardware: #10 SS Pan Head Fasteners  (sold separately) Latches: Locking Slam Latch Material: UV Stabilized Polypropylene Features: 180 degree locking hinges Type: Access Hatch Sealant and mounting Screws are not include