The ChickSafe Premium and Extreme automatic chicken coop door openers come packed with great features for that extra peace of mind! Each has an integrated timer and light sensor, full manual door control and a unique fail-safe mode giving you total flexibility over how and when you want your coop door opened or closed. Great to use in tandem with a vertical sliding door or with the aluminum door kit. The Premium model works with doors up to 4lbs and temperatures from 5 to 105F. The Extreme will work with 9 lb doors in temperatures from -20 to 120F. The Extreme comes with military grade electronics built to function in harsh conditions. Door kit is high quality aluminum with a 9" x 12" opening on 24" vertical tracks. Kit doesn't come with mounting hardware and you must be able to drill through aluminum to install.