Chest Girth 16.5-21.5", Chest Strap 4.5", Width 5/8", Small; The chest strap is not adjustable. For a safe and fit purchase, be sure to check the neck and chest; A properly fitting collar and harness won't leave any room for your dog to chew The harness does not stretch itself. NEVER leave your dog unattended with a harness on Made of high density polyester webbing. Buckles are made from eco-friendly plastic Shop the matching set to complete the look. Its matching collar (B08QCFR8MF) /leash (B08QHJTNL7) sold separately All pictures are taken with our production samples from a size 3/4"(wide) * 20-26"(chest)