The original LifeStraw already hinted with its name that it was essentially a straw through which you drink. However, it was quite a chunky device for a strawwhereas the Sip truly is a slim little unit! Inside the compact exterior is a membrane-based filter with a very typical filtration size of 0.2 microns. - Casing made from stainless steel - Carrying case protects the filter inside a backpack, side bag, or suitcase - Filter lifespan: up to 1000 litersthis strongly depends on water purity, so always choose the cleanest available source - BPA-free product - Filters 99.999999% of bacteria (e.g., E. coli) - Filters 99.999999% of protozoa (e.g., Giardia, Cryptosporidium) - Filters 99.999% of microplastics - Reduces water turbidity The filter meets U.S. NSF 42 standards for chlorine reduction, and US EPA & NSF P231 drinking water standards for filtering bacteria and parasites. Do not let the filter freeze. Freezing will at minimum block the filtration function, and m