This is an excellent product. The local water supply is not too safe; Causes vulcanic tummy and vesuvian tail. This product eliminates the bacteria causing the problem. Has been in daily use for two years now with no problems. In daily use, remember to take it appart and flush it clean weekly. Similarly, on the trail, always clean it before packing away. Never let the outlet pipe anywhere near the inlet pipe to prevent cross-contamination. Before re-assembly always apply a thin coating of Silicone Grease to the threads and exposed aluminium to prevent oxidation (Aluminium does rust).
The tiny tube of grease that comes with the product will not last long so it is a good idea to buy a 100 gram tube of the grease at the same time and pop it into the carrying bag which comes with the filter.
It is also a good idea to put a Stainless Steel Cup with folding handle in the bag so you have something to put your clean water into on the trail. That also allows you to have a cup of tea or coffee on the trail boiled over a wee twig fire. Be carefull not to burn doon the forests.
A word of warning: The Outer-Sleeve is hard plastic; drop it and it breaks; I learned that the hard way. It can take a while to get a replacement part, and though I was still able to make water safe by boiling, water does not taste as good with the impuritys not filtered out. I suggest wrapping some foam sheeting around the filter to give it some protection against accidental dropping. Remember sod's law, what can happen will happen; no matter how carefull you are, some other sod will drop it, so wrap it.
This product is used by the Red Cross, and probably every armed force in the World. Can't think of a better recommendation than that.
Check out this data via Google. When the long? overdue Solar Mega-flare hits the Earth, All electric will fail, which means we lose gas and water too, for they are dependent on electric to operate the supply systems. The experts say the Citys will be blacked out for up to a year, so safe water will not be available except to those that can filter their own.
Electric not working for a year means food cannot be grown or moved to markets. Ships, trains, trucks, tractors, harvesters simply will not work. All industry will close down and all business be forced to close. That's assuming the mega-flare does not cause every city, town, village to burn down.
Life could be pretty rough for a while, and there could be major civil strife caused by lack of food.
A worst case scenario could reduce World population to less then a billion; Bad things happen when your neighbour has to become your next meal.
But at least, with this filter you will not have to worry about your water supply.