Staywell 270US 4 Way Slim Clear Cat Flap is great for any cat or small dog owner. This door is well crafted and will last a lifetime. It provides peace of mind by allowing you to give your pets the freedom to enter and exit the house as they please. Bad weather or unsafe conditions outside are not a problem either. You can enable the lock to keep your pets in our out. It has a completely open setting, as well as an in-only, out-only setting, so you can let your pets in by one direction only. Features: For cats up to 22 pounds and dogs up to 40 pounds. Maximum shoulder width: 7 1/8 inch. 4 locking positions: in-only, out-only, open and locked. Universal fitting for glass, sliding windows, sliding patio doors and doors. Gives pets freedom without inconvenience. Slim design takes up little space.