Conair MiniPro Thermacell Replacement Cartridges Model TC2RBCP 2 Pack. Specifically designed to power our ThermaCELL cordless curler and straighteners, these refill cartridges are essential to have on hand at home and while traveling. The cartridges don’t expire and the butane doesn’t evaporate in the canister tightly sealed from air – so these cartridges can be useful when you really need a spare. Replace low or empty cartridges with a ThermaCELL refill and power your cordless style iron for about another 2–3 months.