Durable Material: Dogs door is made of aluminum alloy material,durable, high strength, good toughness. Lockable: Aluminum pet door with double panel locking, and the dog can enter and exit from both sides, lockable that also can prevent your pet from opening the door easily. Feature: Automatic closing magnetic flap, large size, suitable for large and medium pets in and out. Easy To Install: This dog door is easy to install in windows, doors, cupboards,, simple and elegant. Wide Application: This large dog door is suitable for interior doors, exterior doors, walls, windows and cupboards, etc Size Chart: for Dogs Below 30KG: Outer size: 35cmx44cmx6.5cm/; Inner Door Size: 26.5cmx35.5cm/; Hole Size: 28.3cmx37.1cm/ for Dogs Below 50KG: Outer size: 41cmx54cmx6.5cm/; Inner Door Size: 33.2cmx46. 5cm/; Hole Size: 34.1cmx47.4cm/ Package Includes: 1 Dog Door Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful shopping!