1).High Quality ➯ Solid ABS material. Weather-tight and O-ring sealed deck plates.Anti-corrosive;Ultraviolet resistant. 2).Apply to ➯ This marine access hatch suitable for all kinds of Boats/Yachts. Ideal for interior and exterior applications. 3).Features ➯ Smonth surface,reinforced design with a non-slip surface;180°opening hatches, 4/6/8 inch deck plate. 4).Installation ➯ Deck mount Boat Deck Plate. Rotary witch.Separate cover plate and chassis, easy to install.Pre-drilled countersunk holes (screws not included) 5).Size ➯ 4 inch-Cutout Size 4.4"(112mm) O.D 5.5" (141mm) I.D 4"(101.6mm); 6 inch -Cutout Size 6.5"(164mm) O.D 7.8" (198mm) I.D 6"(152mm); 8 inch-Cutout Size 8.25"(209mm) O.D 9.7" (247mm) I.D 8"(203mm) 6),Package ➯ 1X Boat Deck Hatch & Stainless Steel Screws included. Boat Hatch White 4" 6" 8" Round Non Slip Inspection Hatch w/Detachable Cover for Marine Boat Yacht Truck Rv.-Ideal for interior and exterior applications -reinforced design with a non-slip surface -Easy to install. Rotary witch.Separate cover plate and chassis -No drilling required, direct installation. It is more convenient to use.4 inch -Outside Dimension: 5.5" (141mm) ; Inside Dimension:4"(101.6mm) 6 inch -Outside Dimension: 7.7" (196mm) ; Inside Dimension:6"(152mm) 8 inch -Outside Dimension: 9.7" (245mm) ; Inside Dimension:8"(203mm)