LifeStraw 2-stage replacement filter, old model

I use these with a Nalgene water bottle. It improves the taste of tap water, Here in the UK the tap water is safe to drink but there was a case in Devon of the water being unsafe for a while, so it is a good precaution to have a filter. The filter also has a long life. A bit on the expensive side considering it probably doesn't cost much at all to mass produce. As well as the LifeStraw in my water bottle, I have 2 spares which all together gives me a few years of clean drinking water, both at home or in an emergency.