Special Blue 9x Ultra-Pure Butane Fuel 300ml. Special Blue butane it is cold filtered and run through zeolite molecular sieves to filter out any impurities (impurities are a residue/contaminant – water, air, metals, dirt, other gas products that are removed during the refinement process). Special Blue 9x is run through this process 9 times. It meets both ISO and TUV regulations and is sold with a lifetime warranty. Butane refill for our Special Blue Butane Torches. 9x Filtered Near Zero Impurities Odorless 300ml Volume Variable Nozzle Plastic Cap Made in Europe