With updated features from Gregory, this is one of the most technically advanced, ultra-light, adventure-race packs on the market. Three ways to get at your gear with top-loading, front panel access and bottom access to the main compartment. Foam-padded, contoured shoulder straps with Auto-Adjust harness self-adjusts to fit a wide range of people in various physical activities. Sewn-in, die-cut foam Gullwing waistbelt and StealthLight harness are light weight and low profile. Harness features a wide opening zippered pocket plus attachment points for carrying a water bottle. Hydration compatible, accommodating two 128 oz. reservoirs (sold separately) with dual hydration ports for non-stop hydration. Sport backpanel is made from AeroTech mesh with a vertical chimney vent that helps to move moisture away for a drier experience. Front mesh pocket stretches to hold a helmet, while side mesh pockets store wet shoes or sandals. Zippered top pocket attaches across the back and features an internal battery pocket. Dual ice axe and trekking pole loops with six additional compression lash straps and side bungee cord allow you to carry various technical tools. G Fabric is a high-tenacity nylon fabric impregnated with silicone, so its fibers stretch under pressure instead of locking together and tearing.