Size instructions - Even though the elastic cord design make it fit dogs of different bodily shape,To better fit your dog,please do measure the size of your dog and compare to the size chart or consult with us before placing order. L - Neck girth: 19.7', Chest girth: 22.9-26.8', Length: 15.7' Keep Dogs Warm - Inner cotton-padded layer guarantees softness and greater warmth, especially keeping your pet's belly from autumn and winter cold thanks to expanded wrapping protection Reversible - Dogs can wear the vest on either side, if he or she wants to change style or escape from too much heat Smooth & Lightweight- Sport design of light breathable material with zipper pull and hook & loop fastener. No sharp edges for better wearing experience Safety Dog Vest - Highly visible fluorescent strips, easier to spot in the dark and avoid accidents