It is a four-way cat door that can be used on all doors except glass. Suitable for doors with a door thickness of 20 - 25 mm. It can also be used on thicker doors by purchasing an additional tunnel element. It is plastic. It is a four-way transparent, lockable cat door. What is meant by four directions is that the cat door can be opened both inwards and outwards, only from the inside to the outside or only from the outside to the inside. If desired, the cat door can be completely locked. The area that needs to be cut open for the cat door installation is 19.7 x 21.7 cm. The size of the door in the form of a transparent flap is 18 x 20 cm. The outer frame size of the cat door is 24 x 28 cm. It is easy to install and resistant to outdoor weather conditions.