Perfect for Large Pets: The VOSOIR Large Pet Door is designed specifically for Large dogs weighing up to 110 lbs. It features a 18.7 x 9.92-inch flap opening for easy access, while the wall cutout measures 10.6 x 18.9 inches to ensure a snug fit during installation. The expandable channel accommodates walls ranging from 3.95 to 7.5 inches thick, making it versatile for most homes. Please check the size chart in images 5 and 6 to confirm compatibility before purchasing. 100% Aluminum Alloy Superior Durability: The VOSOIR dog door is made entirely of premium aluminum alloy, unlike iron (rusts), plastic (cracks), or hybrid materials (warps). Advanced welding ensures strength, rust-resistance, and a flawless finish that won t flake.