If you're doing an ultralight overnight or a fast day out and back, the Gregory Z30 Backpack carry's your gear effortlessly with a unique Jet Stream DTS (Dynamic Transfer System) suspension system. The harness system is mounted to the main pack on crisscrossing bars. A tensioning system that stiffens the frame and offers additional Strength when more weight is loaded into the pack, keeps the pack off your back for maximum air-flow, while dynamically adjusting with the weight in your pack. Ideal for fast packing adventures including mountain traverses, hiking, and peak bagging, this pack handles up to 35 pounds of gear comfortably in its 1,800 cubic inch capacity. The Easy top loading main pocket features a hydration sleeve, front zipper pocket, front dump pocket and stretchy mesh outer pockets for assorted Additionals. The hip-belt stash pockets provide easy access of sunscreen, energy bars, MP3, and quick necessity necessities.