From the high mountain passes of Peru's Cordillera Blanca, to high traffic wilderness areas closer to home, 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 domestic emergency use. And because they're individually packaged, they travel well, making the ideal emergency back up to any microfilter. Effective: US EPA approved effective against viruses, bacteria and Giardia cysts. AquatabsAR are not effective against Cryptosporidium. Fast: 30 minute treatment time. Ideal For: Ultralight backcountry travel, international travel, emergency kits. Contents: 30 individually packaged tablets per box. Treats up to 60 Liters.