I have a very fast growing german shepherd puppy. He is bicolor and 7months and he is at about 90 pound mark and still growing. Vet estimates he’ll be about 100lbs when finished growing. So I was iffy getting a vest for him. My shepsky who is very petite at a whopping 50 pounds, wears a large usually so when I got this I thought I could get him a large and just make it bigger. Turns out I actually had to shrink it to the smallest size for both dogs. Once shrunk though it was an amazing harness. My puppy loves it, it isn’t tight on him but tight enough so it’s not loose and gives him lots of free range with it. It also seems to be very comfy for him to casually wear which is nice.