High-efficiency water purification: The outdoor water filter straw can filter up to 10,000 gallons of water, and the maximum flow rate is 550ml/min. You only need to put the filter straw into the water source (stream, lake or bottle filled with water), you can easily and quickly absorb safe drinking water. Effective water purification: The straw water purifier adopts a four-stage filtration system (medical grade PP cotton-coconut shell activated carbon-hollow fiber ultrafiltration membrane-medical grade PP cotton) to achieve a filtering effect of 0.01 microns, which can effectively remove 99.9999% harmful substances and solids sediment etc. Safe material: The portable Personal Water Filtration Survival is made of BPA-free food-grade ABS solid plastic,which can ensure the safety of drinking water and reduce environmental pollution. Portability: The survival water filter weighs only 2.8 ounces (80 g) and measures 1.26x1.26x8.74 inches. The strap and compact and lightweight design are perfect for carrying around. The additional 20 cm long hose is convenient for users to suck water from the kettle/kettle. Wide applicability: The Emergency Water Purifying Device is an indispensable tool for hiking, hunting, camping, mountain climbing, hiking, cycling, boating, riding, backpacking, domestic and foreign travel, field exploration or emergency situations. You can take it outdoors and drink safe drinking water easily.