Best off-the-shelf solution that I've seen
I replaced an old Chicken Guard with a new extreme version including a new locking door. The old door was a custom solution made of wood (plastic is better because it does not matter if it gets wet). The Chicken Guard is a great design. I am an Engineer and I can't think of any way to improve the design. Simple and reliable. However, I think the price is maybe pushing the envelope for some buyers. I would probably not have bought the extreme if I didn't have the good prior experience with the standard unit. The new open on light feature is nice. My old unit only closed on light, but opening was only based on time.