Recommended to Small dogs and Cats Under 13.5kg/30 lbs:This front pet dog backpack carrier is designed for puppyies and cats. Body weight is for reference only. While picking the pet carrier backpack, please measure your pet and choose the right size according to our size chart. Better Breathability:The more open area and all the air mesh padding on this dog carrier backpack ensures breathability, keeping you and your pet from being stuffy and allowing your pet to move more freely without being restrained. Ease to Wear and UseThis dog back carrier backpack features an adjustable full buckle. Prevents our pets from getting caught in old-fashioned zip-up dog carrier frontpack and and doesn't slip off as easily as zippers. This design allows us to quickly put on the pack for pets and adjust to a more suitable size for pets to keep them safe and comfortable. Comfort and SafetyThe chest carrier for dogs uses thickened pearl cotton pads and buttons to move the point of force down from the pet's throat to the chest and abdomen, improving the pet's comfort and safety. And we widened the shoulder straps and added adjustable safety buckles on the back and waist to balance the weight and reduce the burden on the owner. Lightweight and portableadjustable and breathable hands-free pet carrier backpack can be worn on your front side or back side. Provides you and your furry friend with better ways to travel including hiking, traveling, walking, shopping, biking, camping or other more fun outdoor activities without hurting your pet's knees or waist. Measurement In CMPet Back LengthPet Chest GirthPet Inside Leg DistanceS2838-4714-16M3652-7017-20L4560-7822-25XL5466-8627-31Measurement In InchPet Back LengthPet Chest GirthPet Inside Leg DistanceS11.015.0-18.55.5-6.3M14.220.5-27.66.7-7.9L17.723.6-30.78.7-9.8XL21.326.0-33.910.6-12.2 The size may have a slight difference due to manual measurement. Easy to put on and take off - All fast-on and release buckles design,no risk of zipper pinching or slippage Thick Foaming for Saferand Better Support - Instead of elastic band,thick foamingprovides a safer and betrer supporron the neck and chest More Open Areas,Le Restrictions - Widler space, more skin breathingand movement. Comfortable and Breathable - All breathable air-mesh on the privatespot and a tail hole Soft Stable Bottom / Waterproof Surface / Legs out / Adjustable Strap / Quick Release Buckle / Breathable Mesh / Tail Out Step display Put the legs and tail through the holes and buckle up Adjust the strap for per's comfort Front wearing and fasten the belly strap Adjust the strap length to make yourself comfortable Wider& ThickerShoulder Straps - No burning feeling even after prolonged use.Le preure and more comfort Padded Backside - Provides enough comfort and supportat the same fime Adjustable Fasten Buckleson the Back and Waist - Distributing the weight evenly on thebackowaisf, offers a easier and morecomfortable experience Enjoy Every Trip with Your Pet