Nothing is safer or easier to use for purifying the most demanding backcountry water sources than MSR's Guardian purifier. Originally designed for military squads, it brings this highly advanced technology to global travelers, backcountry users, and those stocking emergency kits. Fast and easy to use, this pump purifier offers the added viral protection you need when traveling in developing nations and popular wilderness areas. Its advanced hollow fiber filter offers the most reliable way to purify even filthy water conditions. Add its long-lasting performance and revolutionary self-cleaning ease, and this may be the only treatment device you’ll ever need PRODUCT FEATURES: • Self-Cleaning: Pump self-cleans on every stroke, providing consistently fast flow rates with zero hassle—no backflushing or filter-scrubbing ever required • Extremely Durable: Engineered to withstand heavy use, freezing, drops*, and harsh environments • Long-Lasting: Leading-edge hollow fiber cartridge treats up to 10,000+ liters • Fast & Easy: Pumps a rapid 2.5 liters per minute, offering added viral protection without the need for chemicals, bulbs, batteries, or waiting • Ultimate Protection: Meets NSF protocol P248, testing standard used by U.S. military, for removal of viruses, bacteria, protozoa, and sediment from “worst-case” water conditions
