optimus123 loginI have found that uprht stoves like the SVEA 123, and the Optimus 80 warm up faster, and boil water faster than the Optimus 8R. My opinion is that the uprht burner has aSvea 123 stove. The Svea 123 is a small liquid-fuel (naphtha, commonly referred to as white gas or Coleman fuel) pressurized-burner camping stove that traces its orins to desns first