Water filters with adapters that fit into a wide-mouth water bottle are great. But what if your bottle isn't the standard size, or it's a quart job you picked up at the convenience store on the way to the trailhead? You can still pump up the action without getting your shoes all wet. Just remove the wide-mouth adapter (wiggle back and forth and it'll come off), and tape a small alligator clip to the output hose. For refilling, clip the hose to your bottle and pump away.