All kerosene is not the same for efficient, comfortable heat, use Klean-Strip 1-K kerosene heater fuel. It has no dyes and fewer impurities than 2-K kerosene and is refined to reduce the sulfur content, improve air quality and extend the wick life of kerosene burning appliances. Klean-Strip kerosene meets ASTM 1-K specifications and is suitable for all kerosene-burning heaters, lamps and stoves