This is by far the easiest way to install an automatic doggie door in your home. The Automatic Electronic Pet Door installs in a sliding patio door. Your pet wears an ultrasonic collar that opens the door when it gets within a distance you set (1-10 feet). The door automatically closes and can be turned off or set so your pet can only enter or leave the house. A dual pane window goes above the door. And yes, you can still use your patio door and even lock it up with a deadbolt (to the pet door’s frame).