Flap opening size is 8.25' W x 10.4' H, For SMALL dogs and cats or another small animal. Dog door with magnetic flap closures, built-in magnetic can keep the door automatically closed when your dog leaves. Included sliding door, glass door windows, panels and patio or any other screen areas, allow your pets freedom to get in/out. Our dog door frame is made of high quality ABS material, Especially mesh yarns, the mesh yarn is made of expensive materials and is strong and durable. Just need to fix it with screws and operate according to the instructions.