1).High Quality: Made of ABS material, smooth finish,anti-aging, anti-corrosive,anti-ultravio. 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: Easy to install. Rotary witch.Separate cover plate and chassis 5).Size: 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) 6),Package: 1X Boat Deck Hatch & Screws included. Designed with a non-skid surface allowing horizontal as well as vertical mounting. These inspection hatches are constructed from Polypropylene plastic for extra resistance to the sun, water, salt.