"The Cat Mate Lockable Cat Flap comes in white with a transparent door. This product comes with its own high quality trim able door liner for a neat and easy installation onto all doors, panels and walls to 50mm (2 inch) thick. The Cat Mate cat flap has a 2 way slide open and close lock. It benefits from having a silent action which will not frighten pets or disturb owners and the brush sealed flap with the magnetic closure ensures a draft and weatherproof seal which helps to prevent energy loss. The door sizes: Overall Width: 19.2cm, Overall height: 20cm, Cut Out Width: 16.5cm and Cut Out Height: 17.4cm."