Seven years ago, the US military had a dilemma: its service members, based in the world’s harshest and most resource-deprived locales, needed access to clean drinking water. But there wasn’t a portable purifier on the market that was fit for the job. So they asked MSR to build one. After six years of research and development, MSR had a solution: the Guardian. Now, it’s finally available to the masses. The Guardian’s medical-grade filter removes nearly all viruses, protozoa, bacteria and particulates from any water source. Unlike any other backcountry purifier, the Guardian cleans itself by flushing filter contaminants back into the water source. The filter holds up in freezing temperatures and resists six-foot drops. And the pump is ridiculously fast, sucking up one full Nalgene bottle’s worth of clear, pure water every 25 seconds or so. No wonder Uncle Sam gave it the OK.
Pump rate: 2.5 liters per minute
Lifespan: 10,000+ liters
Crush weight: 300 lbs
Temperature rating: 160 degrees/below freezing