I have the Pullet Shut door. Battery operated but also has a charger if you have electricity to your coop. This is the newly installed door on my current project. My first one was purchased 3 years ago and aside from oil for the hinges occasionally it has operated flawlessly even through the bitter cold Pa. winters. Works on photo sensor opens at daylight, closes at dusk. It has a second open/close at dusk for late-comers. My birds have learned that the door opens and closes a second time and they patiently wait to be let inside.