Aquatimer, Reusable Water Boiling Timer-Changes Color At190 Degrees Of Boiled Water, Simply Drop It In Boiling Water, This Heat Exposure Monitor Changes Colors When Water Has Reached A Minimum Of 190 Degrees F (88 Degrees C) For A Sufficient Length Of Time To Destroy Most Common Water- Born Bacteria Parasites And Bacteria, Great For Back Country Use, Made In USA, Comes From A Non Smoking Home.
eBay