DOOG harnesses are made from DOOG's special neoflex material which is kind of like a lightweight wetsuit harness for dogs.Adjustable in two places, they are soft and comfortable for exercise and great for swimming and playing in the snow. This range of high rvis harness is the perfect choice for active outdoor loving dogs and great for night walks as they are reflective.Suitable for small and medium dogs. To choice the correct size for your dog, please measure their neck and tummy widths with a measuring tape and compare with the size chart.