Here's what other sites are saying:
Each packet treats 2.5G/10L of water. Kills bacteria & viruses and removes dirt, cysts & pollutants. Maintains pure, fresh taste. Easy to use; water is ready to drink after 30 minutes. Also includes a replacement cotton filter cloth.
Having access to safe drinking water is an absolute necessity. Be prepared with these PUR Purifier of Water packets. Includes 6 Pur Purifier of Water packets and a cotton filter cloth. Simple 4-step process provides you with 2.5 gal. of potable water in about 30 min. Each packet treats 2.5 gal. of water, for a total of 15 gal. Effectively removes dirt, cysts and pollutants while killing viruses and bacteria. PUR packets contain calcium hypochlorite (0.542%); 2.168 ppm available chlorine. Works especially well with the PUR Clean Drinking Water kit, sold separately.
PUR Clean Drinking Water Kit
Aquamira Water Treatment Drops
$13 - $14
Katadyn Micropur MP1 Purification Tablets
$10 - $15
Potable Aqua Water Purification Tablets with P.A. Plus
Potable Aqua Iodine and Taste-Neutralizer Tablets
Aquamira Water Purifier Tablets
Potable Aqua Chlorine Dioxide Water Purification Tablets
$11 - $13
Potable Aqua Water Purification Tablets