For dogs ranging 20-80 lbs (9-36 kgs). Measure collar to base of tail. XXL: 26-29in (66-74cm) Completely redesigned in appearance, construction, and functionality, the Kolossus, formerly known as 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. Kolossus 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. Features: Backpacking Pack Conversion Adjustable Shoulder/Torso Height Removable Lap Belt with Hip Pockets & Waste Bag Dispenser Internal Frame with Inner Padding for Dog Comfort Padded Back Panel with Increased Airflow Removable Storage/Dog Back Support Pack with Hydro Port Weight Distribution Straps Side Cooling Venting Zippers Wide Base to accommodate your pet and its tail Detachable Dog Sun/Rain Hood Dog Lumbar Support Straps 300D Ripstop Oxford Polyester Material Matching Hook & Loop Strip for Custom Patch