If you’re serious about spending time outdoors then a good, lightweight microfilter is an essential item.

A microfilter is your physical filtration process out in the wild. Suck dirty water up into it, and the microfilter will pass it through a special pore-sized membrane which then separates any microorganisms or contaminated fluid from potable water.

According to its makers, Seattle-based brand Mountain Safety Research (MSR), the Hyperflow Microfilter is the most efficient microfilter ever created. Certainly its incredibly impressive filtration rate of three litres per minute puts it right at the top of the market. This is thanks to the Hollow Fibre Technology from MSR. The brand’s most advanced tech yet, this uses a cluster of hollow straws with permeable walls.

Water is forced through the walls and filtered and clean water flows out through the central channel. A similar principle is commonly used in municipal water filtration systems, but MSR have miniaturised it - this is one of the smallest filters the brand make.

“Every aspect of the Microfilter is designed to be efficient, lightweight and easy to use."

Every aspect of the Microfilter is designed to be efficient, lightweight and easy to use. This is a filter water system with minimal pumping effort. There’s no strain in the pumping and with that impressive rate of three litres per minute you’ll be drinking in no time at all.

The Hyperflow is lightweight and incredibly compact, which makes it excellent for long hikes. It doesn’t purify for viruses like a couple of other filtering options on the market do, but it does strain out particulate and is effective against bacteria and protozoa.

It features a Quick Connect bottle adapter, which connects to all MSR hydration products and other compatible wide mouth matching containers, making filling your bottles easier. It also comes with an advanced pre-filter to make the filter itself last longer.

The Hyperflow has been on the market for some time now, and it’s always improving with every model they put out, but if you buy one of these you won’t need to replace it in a hurry. The Hyperflow can filter 1,000 litres before needing a replacement cartridge and crucially, it weighs in at just over 0.2kg.


Due to the size and weight of the product, this is also a pump filter you can take on shorter trips with a smaller day pack just as easily as you can fit in a multi-day expedition pack. A filter is often a product negated by gram-counters to save weight on the trails. With the Hyperflow Microfilter, that’s no longer a concern.

MSR Hyperflow Microfilter

Shot on location in Chamonix.