We have tried so many harnesses and this is by far the best! It doesn't have to go over my dog's head (something he finds very aversive). It is comfortable, non restrictive, not bulky or heavy and won't cause him to overheat. It's easy to clean and really well made. If that weren't enough, the team are so helpful. Not site.whst size to get as Colby is a mixed breed, but by sending his girth measurement and some photos they were able to advise me. Really customisable as it comes in 3 parts, all of which can be replaced individually. Once the harness arrived I was able to send photos of my dog wearing the harness so they could check the fit was okay. Worth every penny!