What most people dont realize when building a run-in/ loafing shed is most horses like windows. They are a prey animal and like to see everything around them. The less it looks like a scary dark cave the better. These are heavy duty plexi glass. Theres hay racks, salt block holder, solar powered light. Our horses are always in it since we cut the windows in, i had to chase them out to take the picture. I hope this inspires fellow horse owners!