ANYTHING-PROOF RUCK Quality is life or death to us, and when we build our gear, we only choose tested and proven Specs + Materials that can withstand any environment. That&';s why we&';ve taken our original GR1 rucksack and built it with X-PACA(R) and AquaGuard zippers. Crafted from a fabric initially designed for high-performance racing sails. X-PAC is lightweight, ultra-durable, and waterproof-key features needed to withstand the intense forces of the open ocean. This is what we take to Costa Rica - the most bio-intense space, according to National Geographic. This bag is ready for anything-from the rain-soaked trails of Costa Rica to city streets, giving you the confidence to carry your gear in all conditions.