CONVENIENT LOCK --- button switch is 4-way rotatable, you can easily rotate it in 4 modes with arrow and icons to control your cat's access options: by yourself, outside, only inlet and outlet, completely blocked. IMPROVED BRUSH PULLING Weatherproof --- Provides a fixed groove with snap tabs for the weatherproof brush strip, firmly fixes the brush strip brush. Even if the brush comes off, it is easy to reinsert it into the fixed housing. This greatly helps the brush to reduce noise, stop rain, wind or a pest such as mosquitoes as much as possible. DANGERS OF SCREWS --- Comes with 2 packs of 8 screws each, one with short screws and another with long screws. Please screw them on both sides to avoid breakage, not just one side. You can make 8 screws for the 4 screw holes with the long+long, long+short or short+short mounting, depending on the depth of the door/wall to be installed. APPLICABLE FOR --- Measurement inner 15*15.5. And the exterior size is 19*5.5*22 It can be installed on interior doors, exterior doors, walls, windows, cabinets, glass, etc.