i have this pen as a back up but have never gotten around to using it. cant find the instruction page but i can possibly print one up for you. it uses rock salt or table salt and is probably the best water purifier on the market there are lots of reviews for you to read if you just do a goggle search. these run for 140$ plus tax so 100 is a steal. need the cash to pay some bills so it need to go. it is brand new never been used. i will throw in some brand new high end 13$ batteries. this thing will go for 200+ uses on a pair of batteries. also forget to mention its super light and small for backpack carry. fist 100$ cash gets it.