?Secured at the chest and under the belly, this unique vest keeps your dog cool on hot days while it runs and plays * ?Flexible shoulder material allows the dog to move without restriction * ?Provides 5-10 hours of cooling relief per soaking; extremely lightweight and durable * ?Comfortable, quilted nylon outer w/HyperKewlTM fabric inner, and water repellent nylon liner, and black poly-cotton trim * ?Sizes: XS - Up to 8in Back, Sm - 9-12in Back, Md. - 13-16in Back, Lg - 17-20in Back, XLg - 21-24in Back, XXL - 25-30in Back