Let your outdoor dog , "pull his own weight," with this easy-on/easy-off Kyjen Outward Hound Urban Adventure Backpack. Whether out on the trail or on a walk into town, this pack is loaded with custom features to meet your dogs' needs. Includes reflective accents for your dogs' safety and padded torso strap for maximum comfort and fit. Five storage pockets can hold keys, treats, or cell phone. Dog back pack even has a pet waste pick-up bag dispenser to make clean-up a breeze. Exterior Velcro strap temporarily holds used pick-up bags. Use our biodegradable pet waste bags to keep your outdoor adventurer outdoor friendly. X-Small for dogs under 10 lbs with a 13-17" girth. Small for dogs 10-20 lbs with a 16-21" girth. Medium for dogs 20-35 lbs with a 22-26" girth. (measured around the widest part of the dogs rib cage)