Need an extra cup The Jetboil 1 Litre Short Spare Cup is Flux Ring reg enabled & offers cross compatibility & flexibility Flux Ring reg technology makes it possible to heat a conveniently shaped vessel with extremely high efficiency This patented technology captures the heat of the burner & directs it into the contents of the Flux Ring reg cup rather than into the air as waste For use with the following Jet Boil Cooking Systems SUMO 8482 Mini Mo 8482 Micro Mo 8482 Flash 8482 Flash Lite Zip 8482 LUNA PCS GCS Companion cups are compatible with Jetboil systems only Do not use with other heat sources as it will void the warranty