Pet carrier backpack is designed for carrying small dogs/cats such as Chihuahua, Bichon Frise, Boston Terrier, Maltese, and so on. The key to selecting the correct size is according to your pet's back length and chest girth. Reserve 1" - 2" as much as possible to avoid wrapping the dog too tightly and making it feel uncomfortable. Zippers allow dog carrier backpacks to be opened , which makes it easier to put your lovely pet in or take them out. Also, legs-out and tail-out design keep your pet comfortable and snug. The neck openings are elastic, which are designed to fit your pet more snugly. Dog front carrier backpack is made of breathable mesh and a thick sponge allowing maximum air circulation, so they won't feel too tight or too stuffy. The adjustable and wide shoulder straps can reduce pressure for you and allow you to carry your pet more closely.