99.999% Pure Puretane is the purest butane available because it is THE ONLY butane refined here in the United States. Products from Korea and Europe make purity claims that are simply not true, because they don't have the tight environmental standards that we have in our refineries in the USA. Others claim to be, but Puretane truly is triple refined and 7 times filtered to remove all impurities. You will taste the difference...GUARANTEED!! 300ml per can. 12 cans.