options available - color:Black or white. Size: L :Inside: 18cm (W) x 19cm (H), M:Interior: 15.7cm (W) x 16cm (H), S:Interior: 15.7cm (W) x 16cm (H). Sûand well thought out - the transparent flap allows the pet to see through the door. The outer rain seal is waterproof. The brush strip eliminates the noise when closing the door. The 4-way intelligent door control gives the cat more freedom. The inner edge of the frame is polished to avoid hurting the cat. 4-way switching mode - The flap door can be customized with 4 modes: exit, entry, in and out, and full lock. gives the cat maximum freedom as you wish. Easy to install - The nails and mats included in the set allow you to easily install it in windows, doors, cabinets, panels and walls, etc. Excellent quality - Made of ABS material, weather-resistant, the surface is smooth and durable.