Feature: 1. Anodizing Process: The overall frame of the window is made of heavy duty aluminum alloy with an anodized surface polished to a smooth finish, providing a nice touch and beautiful appearance, ensuring rust and oxidation resistance for a long time. 2. Durable Construction: The light transmitting part is made of 6mm thick smoke gray acrylic glass with rotating fixed handles and 316 stainless steel support rods to ensure the overall sturdiness and durability of the skylight. 3. Sealed Design: The rubber ring can provide complete sealing waterproof performance and shock absorption effect, and the smoke gray glass filters out UV rays while ensuring that light can enter the compartment, enhancing its brightness. 4. Flexible Opening: Adopts push out opening, for 0‑90 degrees can be opened at any angle, rotating handle with switch locking button, and can be used for sunroof, ventilation window, storage compartment, roof, or any location. 5. Versatile Use: 421x421mm hole opening, suitable for 15mm thickness or any thickness of wall, used for ships, yachts, caravans retrofitting and other projects, provides a solution for your old, broken and unsatisfactory windows. Specification: Item Type: Boat Porthole WindowMaterial: Aluminum alloy, Nylon, Acrylic, 316 stainless steelWindow Size: Approx. 486x486mm/19.13x19.13inMounting Hole Size: Approx. 421x421mm/16.57x16.57in Applicable Installation Thickness: Approx. 15mm/0.59in, or any thicknessPush Out Opening Angle: 0-90 degrees Applicable: Suitable for Boat, Yacht, Nautical, RV. Package List: 1 x Window Note: 1. Installation is difficult, it is recommended to find professional engineers to assist in installation to get the best shopping experience.2. Please pay attention to avoid collision when disassembling and assembling.3. Please measure the size before purchasing to make sure it is what you need.