I did a ton of research and purchased this because I love that it easily clips on without the hassle of getting a head or legs through holes. This harness also has the highest reviews at the best price. Harness seems well made but sizing is off so it gets four stars. We followed the size guide and ordered a small for our our pup who is 18'' around her chest and she was swimming in it. Just ordered an xs despite the measurements here indicating it will be too small. These photos are on the smallest setting for the small. Moose is 13 pounds and 18" around her chest. Fingers crossed!