Please note that this listing is for the size S: Neck size 8"- 11", Girth size 10" - 14". Sizing for each dog is unique. We highly recommend you measure your pet precisely with a flexible tape measure to ensure an accurate fit. We recommend one size up for comfort if your dog"s measurement is the higher end of the range listed. * The Maq Seatbelt Harness was 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