MSR – Guardian Water Purifier

MSR Guardian Key Features

• NSF P248 Military Standard: The only backcountry purifier certified to remove viruses under worst-case water conditions
• Self-Cleaning Design: Automatic backflush system maintains flow rate without manual maintenance or filter scrubbing
• Dual-Hose System: Intake hose with prefilter and separate dirty water discharge prevents cross-contamination
• Universal Threading: Compatible with wide-mouth Nalgene bottles and MSR reservoirs
• Field Integrity Test: Unique ability to verify proper function after drops or freezing

MSR Guardian Pros:

• Fastest hand pump purifier available at 2.5L per minute
• No maintenance required — self-cleans continuously
• Removes viruses that standard filters miss
• Extremely durable military-grade construction
• Works in freezing conditions when properly thawed
• 10,000-liter capacity outlasts competitor filters by 5-10x

MSR Guardian Cons:

• Higher weight than ultralight filter options
• Premium investment compared to basic filters
• Overkill for pristine North American water sources
• Bulkier than squeeze or straw-style filters

Recommended For:

• Travelers visiting countries with questionable water infrastructure
• Backcountry users filtering from livestock areas or glacial streams
• Guide services needing reliable group water purification
• Emergency preparedness for extended grid-down scenarios