Give your cat the freedom to come and go as it pleases with this cat flap featuring a 4-way locking system. Slide locks on the bottom of the shutter to set the door to one of the following options: Cat can only enter from the outside but cannot come out Cat can exit but cannot enter (to prevent other cats from entering) #39;enter too) The flap is locked on both sides The flap is completely open and the cat can come and go at will The cat flap is easy to install and is suitable for anyone which wall or door with a maximum thickness of 50mm. Also suitable for small dogs/cats. Features: Size:< /p> S:1919.72cm M:1919.75.3cm L:2523.55.3cm XL:255.527.7cm(please measure your pet before ordering!) The 4-way cat flap is brand new and boxed Material: hard plastic installation method: Tools needed: electric drill, iron saw or power saw, measuring ruler; Step 1: first use a piece of paper to draw the size of the door cover (there may be a few millimeters error); Step 2: Finish the drawing