HIGH-PERFORMANCE FILTER: The BeFree's 0.1 micron hollow fiber microfilter is tested to remove bacteria (99.9999% Klebsiella terrigena) and protozoan cysts (99.9% Giardia and Cryptosporidium) ULTRALIGHT & COMPACT: Ultralight at just 2.3 oz. (63 grams) The collapsible Hydrapak Soft-Flask allows for portability in tight spaces like running short, cycling jersey, and vest pockets. Perfect for ultralight hikers, trail runners, and backpackers. EASY TO CLEAN: The Stay Clean drink nozzle protects against dirt, debris, and bacteria between uses. Simply shake or swish the EZ-Clean Membrane filter in water to remove debris. No backflushing or tools required. FAST OUTPUT: Free Flow Channels create a strong flow rate at 2 liters per minute. Suitable for use by 1-2 people. SWISS QUALITY & DURABILITY- 2-YEAR GUARANTEE: Filters up to 1,000 liters of water before needing a replacement. Highly flexible, BPA-free Hydrapak water flask for durability in rugged conditions.