Light weight but powerful, each Aquamira Water Purifier Tablet purifies one liter (32oz.) or one canteen full of water and is conveniently sealed in an individual child resistant foil pouch. The individual tablet pouches are stored inside our re-sealable storage pouch that eliminates packaging waste and can be packed away almost anywhere. To use, simply drop one tablet into one liter of water and wait the required time. EPA Registered Purifier, Aquamira Water Purifier Tablets contain a patented chlorine dioxide formula that produces a powerful germicidal agent when released in water. When used as directed, Aquamira Water Purifier Tablets meet the EPA guidelines for Microbiological Water Purifiers making it the safest solution on the market. Great for weekend hiking, camping, hunting, or fishing trips. The 20 pack is perfect for 72 hour emergency kits. Aquamira Water Purifier Tablets will not discolor water and will actually improve the taste of treated water. I like these because they can be stored anywhere without the hassles of keeping a glass container safe like you do with other types of tablet containers.