RapidPure Pioneer 1.2-Liter Straw, 2.5-Inch, White The straw tailors your water filter system for a specific trip or activity by increasing or decreasing flow rates Filter is interchangeable with RapidPure Scout for hydration packs with straw Double O-Ring replacement RapidPure filter element The system is simple and easy to use Filters have a rated life of roughly 3750 gallons per inch of media