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MSR Guardian Gravity Water Purifier

MSR Guardian Gravity Water Purifier
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State-of-the-art virus protection in an easy, high-volume gravity system.

The Guardian Gravity Purifier has you covered with safe water around the world, removing viruses, bacteria, protozoa, sediment and microplastics hands-free. Simply hang it while you go about your tasks at the hostel, basecamp or campsite—its 10L reservoir supports the daily water needs of multiple people. Originally designed to protect servicemembers in the field, this rugged purifier handles the abuse of travel and meets the NSF P248 military testing standard.

Ultimate Virus Protection: Meets NSF protocol P248 military testing standard for removing viruses (99.99%), bacteria (99.9999%), protozoa (99.9%), sediment and microplastics from “worst-case” water conditions.

Better-Tasting Water: Two-stage purifier includes activated carbon to reduce chemicals and unpleasant tastes and odors.

Easy to Fill: 10 -liter reservoir is easy to fill at sinks and streams alike; covers daily water needs for drinking, cooking and hygiene.

Simple Cleaning: No backflushing required—simply opening the purge hose flushes the system to clean it and maintain flow rate.

Fast-Flow Rate: Up to 1 liter in 2 minutes with optimal reservoir hang height of 6 feet, 2.5x faster than the next leading gravity purifier.

Engineered for Travel: Rugged, military-grade construction. Compact system fits easily in carry-on luggage and smaller packs.

NSF P248 Testing Standard: The most rigorous scientific certification for proving a treatment device safely removes claimed contaminants from challenging wilderness water sources. Guardian devices are the market’s only purifiers to pass the military standard P248 testing for virus removal.

*Meets U.S. EPA Guide Standard and Protocol for Testing Microbiological Purifiers


Made in the USA of US and Imported Materials

SKU: 13460
Color: Grey
Weight (Standard): 1 lbs 3 oz
Weight (Metric): 0.53 kg / 1 lbs 3 oz
Width (WxLxH) 4 x12x4 in / 10x30x10cm 
Effective against bacteria: Yes
Effective against chemicals/toxins: No
Effective against particulate: Yes
Effective against protozoa: Yes
Effective against viruses: Yes
Filter media: Advanced Hollow Fiber
Filter pore size (microns): 0.02
Flow (L/min): 0.5 liters per min
Cartridge life: 3,000+ liters
Field cleanable: Yes
Field maintainable: Yes
Water Bottle Adapter: Yes
Cartridge replacement indicator: Yes
Material(s): UF Hollow Fiber, ABS
How is a filter different from a purifier?

The main difference lies in the level of protection they provide. Generally speaking, a water filter is designed to remove waterborne protozoa and bacteria, but not viruses. A water purifier is designed to combat all three classes of microbes, including viruses.

Because North American backcountries are regarded as low-risk for viruses, filters typically offer a sufficient water treatment method. In places heavily trafficked by humans or where sanitation systems are poor, the risk for viruses increases. In these areas, such as in developing countries, a purifier is recommended.

Additionally, filters physically remove matter and microbes from the water. In contrast, a "purifier" can employ a variety of methods to do so, from physically removing the contaminants to disinfecting the water of them, through UV or chemical treatments.

Why the two treatment device options? The reason is, viruses are just too small for filters to catch. Far smaller than protozoa or bacteria, viruses slip through the technologies used in backpacking filters. Traditionally, UV light, chemical treatments or boiling were required to deactivate viruses by scrambling their DNA or killing them. Today, new advancements in physical purifiers provide a convenient option to physically remove viruses quickly and easily.

The flow rates of physical purifiers are generally slower than that of filters, because the internal media that removes contaminants has to be small enough to capture tiny viruses. This slows the rate at which water passes through the media, decreasing overall flow rate.

How do I decide whether a filter or a purifier is best for me?

To decide whether you need a filter or a purifier, two important factors must be evaluated: water sources and susceptibility.

When evaluating water sources it is important to keep the following in mind: In general, protozoa and bacteria infect both animals and humans and are transmitted to water sources by animal and human waste. In contrast, waterborne viruses are species-specific and therefore transmitted to water sources by human waste alone. As a rule of thumb, remote areas with few people require (at least) filtration while popular areas with many human visitors require purification. If traveling in developing countries with poor sanitation, purification will be your safest choice.

Susceptibility is another good way to determine needs. If the treated water is to be consumed by infants or young children, elderly, or pregnant or immunocompromised individuals, then it is essential to use a purifier for the highest level of protection. Purification is also best for people who tend to get sick. If you rarely get sick and do not fit into any categories mentioned above, then filtration may be adequate depending on the water source.


MSR Guardian™ Gravity Water Purifier

he MSR Guardian Gravity Water Purifier delivers large volumes of safe, purified water on-demand, making it perfect for international adventurers and group campers seeking reliable viral protection and better-tasting water virtually anywhere on Earth. Shop the Guardian Gravity Purifier here: Using the revolutionary technologies of our original Guardian purifier, this gravity-powered sibling provides the viral protection that’s needed in developing nations and crowded local backcountries. Featuring military-grade engineering, a fast flow and a large 10-liter reservoir, the purifier makes it easy to cover your daily water needs, from drinking to cooking to hygiene, at both urban and backcountry settings. #waterpurifier #backcountrywater #outdoorwaterpurifier

How to Use Your Guardian™ Gravity Water Purifier

Your Guardian Gravity Water Purifier harnesses the power of gravity to provide large volumes of safe, purified water on-demand. Here, we’ll walk you through how to setup and use your brand-new purifier. Shop the Guardian Gravity Purifier here: #waterpurifier #backcountrywater #outdoorwaterpurifier

MSR Guardian™ Gravity Water Purifier Integrity Check

The Guardian™ Gravity Purifier’s filter media is made of advanced and tiny hollow fibers. These fibers can be damaged if the cartridge is dropped or if you allow the cartridge to freeze after it’s been used. If either of these has happened, you’ll want to perform the integrity test to ensure the cartridge is still safe to use. We’ll show you how in this video. Shop the Guardian Gravity Purifier here: #waterpurifier #backcountrywater #outdoorwaterpurifier

Part Numbers

040818134603 13460 WAT476705501