Hiking equipment
According to Tom Brown, the basic plan for survival is in the order of shelter (including clothing), water, fire, and food. Cody Lundin writes about the "Rule of 3s"; this relates to human survival without basics: three minutes without air, three hours without shelter, three days without water, or three weeks without food.
LifeStraw
The LifeStraw water filters are designed by the Swiss-based Vestergaard Frandsen. While originally developed for people living in developing nations and for distribution in humanitarian crisis, the LifeStraw has gained popularity as a consumer product. The LifeStraw is now used as a tool for survivalists and packed in emergency preparedness kits in addition to being used to help combat clean water scarcity worldwide. LifeStraw personal filters can provide clean water for up to a year, and the LifeStraw Family filters a maximum of 18,000 litres of water, providing safe drinking water for a family of five for up to three years.