I bought the horse/adult size and it fits my 13.2hh 760lb pony mare wonderfully. There's plenty of room to adjust bigger or smaller so I think this would fit a wide variety of horses. I was worried the adult would be too big since my mare is a pony and I'm a small adult, but it fits her fine. This pad is super comfy to ride on and seems to be really good quality. I can't attest to the durability since I just got it but I'm very happy with it. It's beautiful, doesn't slip, and is convenient to just throw on real quick.
Rating: [5 of 5 Stars!]