This is the greatest item I ever purchased for my survival supplies. It is in with my ‘Bug Out’ items but I have tried it. This filter works amazingly well… this water filter is made of heavy duty materials and is ideal for long lasting continuous use even under extreme circumstances. The silver impregnated ceramic element is effective against bacteria and protozoa. The Katadyn Pocket is the only water filter with a 20 year warranty. It is easy to clean and care for. Below isa link to where you can find this filter and others like it on Amazon.com.