The only approved butane recommended to fuel all Master butane powered heat tools including all Ultratorch and Microtorch products. Butane is produced using purest refining method possible. Special non-clogging formula permits extended use. Contains no CFCs (chlorofluorocarbons). Will not harm the ozone layer. Each canister comes with a convenient single piece universal filling tip. Available in two sizes: 51⁄8 oz. (145 g) and 15⁄16 oz. (26.5 g) canisters.