Size S: Chest girth: 10.5"-12.4", Neck girth:7.4"-9.3", Leash size:59" (150cm). The harnesses are made with easy-to-secure Velcro, which makes outfitting your cat simple. The baby's special soft Velcro is used in the neck and chest, a plastic closure is added to the neck to prevent the cat from escaping after get rid of the Velcro.