Nothing is safer or easier to use for purifying the most demanding backcountry water sources than the MSR 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. Features and Specifications 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. Fast & Easy: Pumps a rapid 2.5 liters per minute, offering added viral protection without the need for chemicals, bulbs, batteries, or waiting. Self-Cleaning: Pump self-cleans on every stroke, providing consistently fast flow rates with zero hassle—no backflushing or filter-scrubbing ever required. Long-Lasting: Leading-edge hollow fiber cartridge treats up to 10,000+ liters. Extremely Durable: Engineered to withstand heavy use, freezing, drops*, and harsh environments.*Withstands MSR water lab drop testing: 6 ft. to concrete. Colour: Smoke Weight: .490 grams Flow Rate: 2.5 litres/minute Cartridge Life: 10,000+ litres Length: 20.62 cm Width: 7.5 cm Height: 11.25 cm Effective Against Bacteria: Yes Effective Against Protozoa: Yes Effective Against Viruses: Yes Filter Media: Advanced Hollow Fiber Filter Pore Size (microns): 0.02 Field Cleanable: Self-Cleaning Field Maintainable: Yes Water Bottle Adaptor: Yes Cartridge Replacement Indicator: Yes Country of Origin: Made in USA of US and Imported Materials MSR Guardian Purifier - Portable Hiking Water Filter and Purifier