This mixture of butane was designed for use in high-altitude regions where oxygen is less abundant. High Performance butane may also be used in low-altitude regions for those looking to increase current flame height. Over time, burner valves may become clogged, causing lower flame heights, this mixture of butane provides an additional boost to help clean out those built-up impurities in the gas line and burners to achieve taller and stronger flames Note: Butane must be shipped using approved ground methods. Please consider the delivery time prior to placing your order.