Chest Girth 16.5-21.5", Chest Strap 4.7", 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, which imparts softness and durability to the product. This harness is a single product. Its matching collar (B00HWQNUDO) /leash (B00HWQRKMG) sold separately All pictures are taken with our production samples from a size 3/4"(wide) * 19.5-25.5"(chest).