Dogstory Comfortable Mesh Pet Legs Out Front Backpack,pet Carrier for Cat or Dog,2 Color,3 Size to Choose 1.Breathable mesh fabric: Soft ,Sturdy and Lgihtweight. Make it comfortable and safe to wear. 2.Velcro, zipper and elastic side openings to hold your pet secure and comfy inside; Additional interior lock to fix your dog's collar for not skipping out. 3.Adjustable shoulder strap, with buckle to fasten around your waist; Two ways to carry at front & back. Order it now and start to enjoy a hands-free pet-transportation journey, new and exciting experience! 4.Size:S- chest circumference:38cm,distance between front leg hole and back leg hole:12cm,for pet between4.5-7 pounds.--- M- chest circumference:44cm, distance between front leg hole and back leg hole:14cm, for pet between7-10 pounds.--- L - chest circumference:50cm,distance between front leg hole and back leg hole:18cm,for pet between 10-13 pounds.--- (PS:There is a user experience report for reference in the description, which can help you to choose for size.)