UCLA Bruins NCAA Dog Jersey Small Jersey Sizing - Length (12-13"), Girth (14-18"), Neck (10-13") Medium Jersey Sizing - Length (14-15"), Girth (16-20"), Neck (11-14") Large Jersey Sizing - Length (16-17"), Girth (20-24"), Neck (13-16") Extra Large Jersey Sizing - Length (18-20"), Girth (27-30"), Neck (16-21")