The Pet Life Shearling DUGGZ Dog Shoes is composed of a Suede and Sherpa Outer shell and inner lined with Thinsulate insulation. Features a Back Zipper and Wrap Around Velcro for Easy On Off access and added support and comfort. Features Rubberized Grips. These Shoes are essential during the colder weather climates protecting your dogs paws by helping prevent Frostbite. Essential for Dogs in Recovery and especially elder dogs and puppies. Sizing Instructions: Measure the Sole of your Pets Foot - Length x Width (inches): XS: 2.15 x 1.51 SM: 2.28 x 1.61 MD: 2.46 x 1.87 LG: 2.64 x 2.01