Military-grade water purifier for wild adventures
Most water purifiers make you choose – fast flow rates but questionable virus protection, or thorough purification that takes ages and clogs constantly. The Guardian Purifier refuses that compromise. Originally engineered to meet military standards, it’s the ideal companion for anyone travelling where water quality is highly questionable. The hollow fibre filter physically removes viruses, bacteria, protozoa, and sediment at 2.5 litres per minute. Best of all, it’s also self-cleaning: every pump stroke pushes clean water forward whilst backflushing contaminants out, so flow rate stays consistent throughout the cartridge's 10,000+ litre life. No scrubbing filters, no backflushing faff, no watching performance gradually trickle away to nothing. Works with water bottles and hydration bladders, and takes care of even the "worst-case" water sources – the brown, silty, definitely-wouldn't-drink-that-looking stuff.
- Meets NSF protocol P248 military testing standard for virus, bacteria, protozoa removal
- Pumps 2.5 litres per minute for rapid water treatment
- Self-cleaning on every stroke maintains consistent flow throughout 10,000+ litre life
- Advanced hollow fibre filter physically removes contaminants to 0.02 microns
- Military-grade durability withstands freezing, drops, and harsh environments
- Works with water bottles, hydration systems, and cooking pots
- No backflushing or filter-scrubbing maintenance required
| Weight | 490 g |
| Dimensions | 21 × 11 cm |
| 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 | 0.02 microns |
| Flow Rate | 2.5 L/min |
| Cartridge Life | 10,000+ L |
| Field Cleanable | Self-cleaning |
| Field Maintainable | Yes |
| Water Bottle Adapter | Yes |
| Cartridge Replacement Indicator | Yes |
A staple of multiple expeditions for more than 50 years, MSR gear is trusted by climbers, mountaineers, explorers and researchers in some of the highest and coldest places on earth. The brand has earned an enviable reputation for turning out reliable, durable, high-performance kit – and has come a long way since its founding by Seattle engineer and lifelong mountaineer Larry Penberthy in 1969. Back then, MSR – or Mountain Safety Research, to use its full moniker – was solely focused on improving the safety of climbing equipment. Why? Because Larry knew that better equipment meant greater adventures.
Since then, the product range has grown hugely, but the core ethos remains the same. That’s why MSR gear is characterised by its user-led design that prioritises functionality, simplicity and reliability, wherever you roam in the great outdoors – whether you’re on a weekend camping trip, or perched on a portaledge 2,000ft up one of the world’s big walls.
