Features: 1.ADVANCED AND SAFE TECHNOLOGY: With Membrane Solutions's advanced safety filtration membrane technology, this filter straw is divided into four stages, including coarse filter screen, Polypropylene nonwovens, coconut shell activated carbon and hollow fiber ultrafiltration membranes. It is able to remove all visible solid sediments,reduce 99.99999% of harmful substances, and improve the odor, ensuring the safest water in the worst environments. 2.PORTABLE: This straw filtration at only 6.7? long and 1.1? in diameter fits any bottle, cup, or glass. It weighs just 5 ounces and fits in the palm of your hand,pocket, gym Bag, backpacks, survival packs and Purses. You can take it anywhere you want conviniently. 3.OPTIMUM PORE SIZE: Our pore size is 0.176 microns. We all know that the smaller pore size, the higher the filtering accuracy, but the lower flow rate. Also we know that a 0.2 micron aperture is enough to filter out 99.99999% of the tiny material. Compared to the 0.1 micron filter straw on the market, our 0.176 ?m pore size filter straw maintains the optimum flow rate while maintaining the same filtration accuracy. 4.VARIOUS APPLICATION: Mini and lightweight filtering system is ideal for recreation, hiking, camping, scouting, domestic and international travel, and emergency preparedness. Specifications Technology: Hollow-fiber UF membrane coconut activated carbon, 4-Stage Filtration Tech Material: BPA Free ABS?membrane?carbon etc Filter Accuracy: 0.176 micron FlowRate: 450ml/min Filter Lifespan: 264 gallon Portable Size: 6.7 x 1.1 inches Weight: 70g (2.5 Oz) Free of chemicals Package included Water Filter Straw?With the lanyard)