Doggy door for sliding glass doors

My stepdad made this for my rabbits, so it would be good for cats or very small dog breeds. The wood panel slides snuggly into the patio door and stays in place without any hardware. My patio door is 7ft tall. The door is closed there. Under the closed door is a flap for your pet to pass through easily. There is weathering attached to the side of the door to avoid drafts blowing through.