Alfie Pet by Petoga Couture - Maq Car Vehicle Safety Seat Belt Harness with Tether and Microfiber Fast-Dry Washcloth Set Best fit neck girth: 13" - 17", breast girth: 17" - 23". Tether measures 13" - 23" in length and 1" wide. Weight less than 30kg. Sizing for each dog is unique. Similar to our clothing and accessory, medium size from one designer is not the same for another. For example our 9-pound yorkie model usually fits either one of three sizes (i.e. XS, S, M) depending on the designer. We highly recommend you measure your pet precisely with a flexible tape measure to ensure the best fit. Contact us if you have question. We are happy to help. Designed for pet's safety while riding in vehicles. Made from strength-rated material with padded safety vest. Durable buckles and adjustable strap. Any seatbelt can go through the harness back and install easily in all vehicles. Comes along with a seat belt tether. Can also be used as regular harness. Alfie is a registered trademark and is exclusively distributed by Petoga Couture. Alfie trademark is protected by US Trademark Law. Use is strictly prohibited. Other seller offerings are counterfeits, they will not be identical to what is advertised here. Petoga Couture ship from US thru Amazon therefore all orders with them are eligible for FREE Super Saver Shipping and Prime Shipping Upgrade.