Jetboils Jetpower Fuel Canisters boast a high-performance blend of propane and isobutane that burns with maximum efficiency and minimum consumption. Propane provides higher vapor pressure for cold-weather performance and Isobutane offers constant pressure as the fuel level lowers. Per 12. Available: 100 gram, 230 gram, 450 gram. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Size: FUEL 100 GRAM 12PK. Type: Fuel.