KLYMIT Motion 60 Backpack ULTRALIGHT AIR FRAME TECHNOLOGY allows for a dynamic carry to increase energy, stiffness, comfort, and customization Rugged, lightweight, water resistant backpack with YKK zippers and is Hydration Compatible MOST COMFORTABLE PACK ON THE MARKET: Conforms perfectly to the shape of the back while utilizing the natural properties of gravity and air INNOVATIVE DESIGN: Integrated air pump allows you to adjust the pressure on the move for full load transfer and stability; Air Frame also provides great lumbar support SPECIFICATIONS: Weight: 2.5 lbs; Volume: 60L +3L pocket; Load Rating: 55lbs; because we are authorized sellers of this product, it includes a limited 2 YEAR WARRANTY