Various sizes: Please measure the GIRTH of your dog before taking this dog hikking backpack home: S: 22.83-25.59''(58-65cm), M: 26.38-30.71''(67-78cm), L: 32.28-38.58''(82-98cm), XL: 33.86-42.91''(86-109cm). High quality and comfortable: Made of breathable middle mesh and soft mesh, this dog saddle bag offers your lovely dog a cool and comfortable feeling. Light weight and washable: This saddle backpack is perfect for outdoor hiking and travel walking in all seasons. It is washable, durable and can be used for a very long term.