•The flushable water purification straw uses a hollow fiber ultrafiltration membrane filter element with a filtration accuracy of 0.01 micron, which can intercept 99.99% of E. coli, and an additional carbon fiber filter layer improves the taste of the water •It is suitable for filtering natural fresh water such as river water, rainwater, and well water. The filtered water can be drank directly •The total filtered water it provides is about 1000-2000L (varies depending on the water quality) •It can be used when traveling, playing sports, hiking, camping water filter, engaging in outdoor work, during a natural disaster, for emergencies Specification: •Product size: 170*33mm •Applicable water source: fresh water without chemical pollution (category 1-3 surface water) Package included: •1 x Water Filter •1 x English User Manual •1 x Strap •Other things not included