This is one of those items everyone could easily add to their pack. It's 9" long and weighs only 2 ounces. As long as you have a water source, you can have clean drinking water. It's basically a large straw with a filter inside that traps out 99.9% of protozoa and bacteria from up to 1000 liters of water. On top of that, for each LifeStraw® you purchase, one school child in a developing community receives safe drinking water for an entire school year. We first used the Lifestrpaw on our trip to The Enchantments where we didn't want to have to haul water up Aasgard Pass. Drinking ice cold water straight from a melting glacier after a long hike is an amazing sensation.