I bought a size small for my adopted rescue dog when she was 6 months old. I love the brown/tan color, as she is a red merle with mostly brown and tan and white, so it blends in with her fur, and the velvet looks amazing. She outgrew it so I purchased the Medium size in the same brown/tan color and it is awesome. It is the most secure harness, the dog can't slip it, and with the buckle at the top where the lead clips to, it gives me peace of mind that if the buckle breaks, the lead will still be clipped and hold the harness together. I have used step-in harnesses in the past and didn't like them, but this one fits really well and I've taught my dog to "sit-up" to put both paws in at the same time which makes getting it on easier. I've bought other colors for my other 3 dogs and love them all! I do wish the Black came with black or darkened silver color hardware instead of the rose gold, but otherwise love this harness so so much. We use for going off our property only, and don't leave it on the dogs otherwise, so I expect it will last quite some time.