VARGO - TITANIUM TI-BOILEREfficient, Versatile Cook System Triple your cooking capability and efficiency with the Vargo Titanium Ti Boiler. By pairing our popular titanium Ti lite 900 ml Mug with a titanium 400 ml lid pan weve created a double boiler system that allows you to cook two items at once to save both time and fuel. The lid pan is uniquely designed to nest on top of the mug to utilize the captured heat from the mug to cook food slowly preventing burning.