Pets want to help save the environment too! Short sleeved tee made out of organic cotton. Sizes: XS, S, M, L, XL. PLEASE NOTE: If your dog is in between sizes please order a size up.size length neck girth XS 7 - 9 7 - 9 11 - 14 S 9 - 11 9 - 11 14 - 17 M 11 - 13 11 - 12 17 - 19 MM 11 - 13 11.5 - 13.5 18 - 20 L 13 - 15 12 - 14 19 - 21 XL 15 - 17 14 - 15 21 - 23 *The units are in inches. *Length is the standard measurement for all dog apparels. *Length is measured from the base of the neck to the base of the tail. *MM is designed for chubbier dogs.