Fairwin Service Vest Dog Harness - Adjustable Nylon with Removable Reflective Patches for Service Dogs Large Medium Small Sizes Comfortable Design-Padded back & neck straps completed by breathable mesh lining. Best service dog vest for your lovely friend. Solid Design and Craftsmanship - Made from sturdy, high quality nylon, with removable "SERVICE DOG" patches, a stainless steel D-Ring for leashes and ID tags and an upgraded top-mounted standing handle, this service dog jacket is a must have item for your dogs wardrobe. Gift For Your Dog-This service dog vest will be the best gift for your dog. Size Measuring - Use a soft measuring tape. Measure all the way around the rib cage, full circle. Your dog must be standing. Check out our helpful Size Chart in Picture 5th for reference. As a general rule of thumb, if your dog's measurement falls on the maximum end of one size, always order the next size up. Best Warranty20 months warranty and 60-day hassle-free return policy.