MSR HyperFlow replacement filter cartridge — Hollow-Fiber microfilter cartridge, NSF P231-certified, lightweight USA-made

The MSR HyperFlow Replacement Filter Cartridge is a factory-made spare part designed to revive the performance of an MSR HyperFlow Microfilter. Lightweight and made in the USA, the cartridge uses hollow-fiber membrane technology that has been independently tested to meet NSF Protocol P231 standards for microbial reduction across its life span. It is field-serviceable with routine backflushing to keep water flowing quickly during multi-day trips or regular household preparedness use.

How does this cartridge restore flow and filtration performance?

Swapping in a new Hollow Fiber cartridge returns your HyperFlow filter to near-original output and microbial reduction capability. The cartridge replaces the internal membrane that captures bacteria and protozoa while allowing water to pass through at high rates when maintained properly.

• Designed to fit MSR HyperFlow housings exactly for an easy replacement.
• Backflushable to sustain approximately 3 L/minute flow (one liter per ~20 strokes).
• Rated to last up to 1,000 liters under normal use before replacement is recommended.

What contaminants does the hollow-fiber membrane block?

The cartridge is engineered to remove particulate microorganisms using densely packed hollow fibers. Independent testing to NSF Protocol P231 shows high log-reduction performance for common bacteria and protozoa relevant to wilderness or travel water sources.

• Certified to remove 99.9999% of bacteria and 99.9% of protozoa under P231 testing conditions.
• Effective against typical biological contaminants found in surface and untreated water.
• Not intended or certified to remove viruses, chemical pollutants, or dissolved solids.

How do I maintain the cartridge in the field to keep it flowing?

Maintenance is straightforward: regular backflushing clears trapped debris and prolongs the usable life of the membrane. Keep a simple backflush routine and replace the cartridge when flow slows significantly or after the rated service volume is reached.

• Backflush with clean water frequently—aim for a burst of backpressure after filtering turbid sources.
• Expect consistent performance when you maintain approximately one liter per 20 strokes (about 3 L/minute).
• Store dry between trips and replace the cartridge after roughly 1,000 liters or when flow drops.

Who is this for? The MSR HyperFlow Replacement Filter Cartridge is for hikers, backpackers, international travelers, and emergency-preparedness users who already own an MSR HyperFlow Microfilter and need an authorized, high-quality replacement membrane. It’s also suitable for field technicians and outfitters who want a lightweight, easy-to-install spare that restores certified microbial reduction and fast flow for groups or prolonged outings.