Completely redesigned in appearance, construction, and functionality, the Rover 2 is THE big dog backpack carrier that now doubles as a backpacking pack. It is ideal for carrying medium to large dogs and available in sizes L-XXL. Rover 2 technology is top of the line in pet/human safety and comfort. Adjustable shoulder/torso sizing makes this backpack more suitable than ever for all body types (as long as you can withstand the weight). When you’re not carrying your 4-legged friend, the backpack easily converts to carry your gear with up to 60 liters of space. Use this backpack for strenuous hikes, bike rides, and public transit. Safety: All K9 Sport Sack carriers are specially developed under the close direction of animal professionals, veterinarians, dog trainers, and outdoor product engineers to be ergonomic, safe, and strong.