The portable water filter straw is a mini water filter system that turns rain, lake, mountain springs, streams, and river water into drinkable water immediately. It can be used for activities like travel, hiking, cycling, hunting, camping, expedition, climbing, fishing, survival, military, and emergency. It has a .2 micron hollow fiber ultrafiltration membrane and is BPA free. The water filter straw has a portable design which makes it easy to carry. It has a cap with a dust free design and easy operation just stick in a body of water and suck. It features a multi-layer filtering technology and the antibacterial activated carbon filter will provide you with 400ml per minute of fresh clean water. The filter capacity is 1500L of liquid. It measures 6 ¼ x 1 ¼. You should have a straw in your bug out bag for each person in your household and its not a bad idea to keep one in your car.