Blueberry Pet Step-in Nautical Flags Inspired Designer Dog Harness, Chest Girth 15.5" - 19.5", XS/S, Adjustable Harnesses for Dogs Chest Girth 15.5-19.5", Chest Strap 4.5", Width 5/8", XS/S; 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. However, it comes with matching collar/leash to complete the look. Collar and leash sold separately. All pictures are taken with our production samples from a size 3/4"(wide) * 19.5-25.5"(chest).