Aquatabs water purification tablets quickly and reliably purify drinking water on-demand. They're effective against viruses, bacteria and Giardia cysts, providing safe drinking water in just 30 minutes. Ideal for ultralight backcountry travel, they're also great for international travel and emergency kits. And because they're individually packaged, they travel well, making them the ideal emergency back-up to any microfilter.FeaturesUS EPA-registered in all 50 states; effective against viruses, bacteria and Giardia cysts.30-minute treatment time.Each tablet treats up to 2 quarts of water depending on conditions.Ideal For: Ultralight backcountry travel, international travel and emergency kits.