NO TWO DOGS ARE THE SAME - Don't guess on the size. Use the size chart along with the "Measuring Your Dog" size guide. The chest measurement is the most important for this vest COMFORTABLE - Soft flexible material when wet provides your dog with a feeling of comfort on hot days COOLING EFFECT - Protects and cools the heart region and chest which is vital for circulation ABSORBENT - Twice the absorption capacity than standard terry cloth coats. Stays cool longer SMALL SIZES - Sizes XXS to Small have attachment loops for a leash making the vest a convenient harness