MSR® Aquatabs Style # 00565. 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.