While you need potable water, you no longer need to expend time and energy pumping old school filters! Just fill the gray water bag and let gravity do the work and enjoy your water in as little as 1.5 minutes. We here at Huckleberry Arms were not content to sell these systems incomplete without a bite-valve like you will find elsewhere, so have sourced and are now including one with each system free of charge as an added benefit of shopping with us!