This is the original "straw" filter. The ultra-light, award-winning design allows you to be prepared wherever you find yourself. It is ideal for back country adventures, emergency preparedness, travel and austere environments. The straw filters out bacteria, parasites, and micro-plastics to help prevent waterborne illness. You can drink water directly from lakes, streams or rivers through the straw, or fill containers with water and drink through the straw while you're on the move. The LifeStraw does not have a shelf life and is rated to filter up to 1,000 gallons (4,000 liters) of water, enough to survive for 5 years! An affordable, dependable product for a wide variety of situations.