It's amazing. No matter how long and hard I thought about all the little details I wanted my coop (https://www.backyardchickens.com/forum/viewtopic.php?id=542609) to have I still forgot to raise the pop door so I can do deep litter! Currently it sits flush with the ground and measures 13" x 16". The opening is framed in place so moving it is more trouble than it is worth. If I put a 6" board in front of it will my large breed chickens be able to squeeze through a 10" high opening? I'm new to chickens and can't quite grasp of how big a full grown one is or how they maneuver!