Size M Recommended for 5 lb≤Small Dog & Pet≤Length of the back less than 9.8 inches, weight less than 9 lb: Size M:14.6"(L)*8.3"(W)*16.5"(H). Please DO measure your pets and choose according to the SIZE CHART and Try-on Report Multi-Pocket Design: Pet dog backpack side and front pockets with zipper help store phone; wallet; bank card; and a collapsible pet bowl; snacks; poop bag; and other necessities Reliable Safety & Detail Design: Puppy carrier backpack built-in security leash with clamp can connect with pet's collar which will prevent pet get out and protect the safe of pet. Pet hiking carrier backpack comes with both waist and chest buckles to give you extra support and prevents falling As a Front or Back Carrier: WOYYHO dog carrier backpack easy to load/carry as a front/back carrier. It's made from breathable mesh and polyester fiber. The adjustable neck hole window design on the top allows your pet to keep the head extended, making it ventilated and visible, interacting and communicating with you Thick sponge filled & Removable bottom plate: The dog front carrier backpack which is ergonomic and very comfortable, reducing the burden on the shoulders and back of the owner. Soft and removable washable pads and removable solid bottom covers add comfort, prevent sagging, maintain stability, and are easier to replace/clean Dog Cat Pet Carrier Backpack Travel Carrier Bag Front for Small Dogs Carrier Bike Hiking Outdoor