Water Filter Straw

A personal water filter the size of a marker pen. Put one end in a stream, a lake or a suspicious puddle and drink through the other. Five filter stages, ending in a hollow-fibre membrane, take out 99.99999 % of bacteria such as E. coli, together with microplastics and fine particles. A layer of activated carbon deals with chlorine taste and smell.

It is tested and certified by NSF International against NSF/ANSI 42, 372 and 401. In plain words: better taste, lead-free materials, and proven reduction of microplastics. That is a lab certificate, not a sticker.

The mouthpiece and the bottom cap unscrew. The bottom thread fits any standard 28 mm bottle, so you can screw it onto a plastic bottle and squeeze, hang it under a gravity bag, or drink straight from the source. To clean it you backwash with a bottle of clean water. No syringe, no tools.

One straw filters up to 5,000 litres before it needs replacing, at roughly half a litre a minute. It weighs about 57 grams, comes with a lanyard and clip, and is BPA-free. Hiking, camping, travel, the emergency drawer at home: it belongs in all of them.