Newly redesigned, the Kolossus is THE WORLD'S BEST big dog backpack carrier that also doubles as a backpacking pack. Size XL is ideal for carrying medium to large dogs with top of the line technologies in pet and human safety and comfort. Adjustable shoulder & torso sizing for all user sizes and maximum comfort. When you’re not carrying your 4-legged friend, the backpack converts to carry your gear with up to 60 liters of space. This pack is ideal for serious use in outdoor or urban environments.