Feature: 1. ACRYLIC GLASS: Boat portlight window is made of acrylic glass, which is anti aging, anti UV, anti corrosion, anti deformation and anti yellowing, long lasting. 2. OVAL DESIGN: Marine portlight window is designed with oval eye shape to allow more light to enter the cabin and increase the brightness of the cabin. 3. SEALED AND WATERPROOF: Marine hatch porthole window is completely sealed and waterproof, with locking fixed handle, with insect screen and frame. 4. OPENS AT ANY ANGLE: Boat portlight hatch window can be opened at any angle from 0‑180 degree, allowing you to enjoy the scenery along the way. 5. SCOPE OF APPLICATION: Opening boat portlight window can be used for ventilation window, suitable for small boats, yachts, ships and RV. Specification: Item Type: Marine Portlight Window Material: Aluminum Alloy, ABS, Acrylic Porthole Size: Approx. 470x210mm / 18.5x8.3in Installation Opening Size: Approx. 405x150mm / 15.9x5.9in Suitable For Installation Thickness: 10-40mm /0.4-1.6in Wall Thickness Application: Transparent Window Can Increase The Brightness Of The Cabin, Can Be Used For Ventilation Window, Completely Sealed And Waterproof, With Locking Fixed Handle Suitable: Good For Boat, Yacht, Ship, And RV Installation Instructions: The Window Is Inward Opening Type, The Fixed Frame Is Installed Outside The Cabin, The Glass Surface Is The Inside Surface Of The Cabin. Package List: 1 x Marine Portlight Window 1 x Mounting Frame Note: 1.Please allow some error due to manual measurement.2.Installation is slightly more difficult, it is recommended to find professional engineers to assist in the installation.