lori, there was mention from a fellow bper on another small group I belong to and he mentioned also about a connector for hooking up a filter to a bladders outlet hose. That would be handy when perched on a log or group of unfriendly rocks trying to filter water into a bladder. I just use a bottle then. I need to search that out for when I bring a filter on shorter trips or where I suspect the water to be less pure.