Using this pet screen door is a breeze. First, find a suitable metal or plastic screen where you want to install it. Make sure the screen area matches the door dimensions of 24 cm x 29 cm. Attach the door using the included slide - lock for a secure fit. Your pet can then freely pass through the flap opening of 20 cm x 23.5 cm. Just note that this door is designed for pets up to 13.6 kg, so larger pets might not be able to use it comfortably. For maintenance, simply wipe the door with a damp cloth regularly to keep it clean. Avoid using harsh chemicals as they may damage the door's finish.