The HydraPak UltraFlask+ Filter Cap turns a compatible 42mm HydraPak soft flask into an on the go water filter. Screw it on, fill from a stream and keep running.
Ultra runners and long distance folks like being able to refill from natural sources instead of carrying all their water. This adds that without a separate filter.
Trail runners and ultra athletes on long runs and remote routes. Lets you run lighter on the Monarch Crest.
