Size Chart:<br>X-Small: Chest girth: 8.0-13.5 inches; Neck girth: 5.0-9.5 inches. <br> Small: Chest girth: 13.0-20.0 inches; Neck girth: 6.0-17.0 inches. <br> Medium: Chest girth: 20.0-26.5 inches; Neck girth: 12.0-18.5 inches. <br> Large: Chest girth:29.0-33.5 inches; Neck girth: 19.0-25.5 inches. <br>Healthy and safe materia bring the best experice for you dogs. <br>Cowboy rider dog custome can arouse the dog's nature, thus enjoying it. <br>This a good choice for your family and friends to give them as a gift.