Jetboil Jetpower 4-Season Fuel Blend, 100 Gram High-performance propane/isobutane four-season blend Propane provides higher vapor pressure to the fuel for better performance in cold weather. Iso-butane provides more constant pressure as the fuel level gets low Jetpower microcanisters stow conveniently within the 1 liter cooking cup and the 1.5 liter pot. This item is not for sale in Catalina Island