The Trangia Spirit Burner is the most versatile and user friendly alcohol burner on the market. Besides having a track record of reliable service that spans decades it also has a couple of uniquely useful features. The simmer ring allows the burner to adjust from full to simmer and extinguishes the flame when closed completely. The twist on cap with o-ring seals the burner so you don't have to empty unused fuel between uses and prevents evaporation - less fuel wasted means less fuel you have to carry. Includes burner simmer ring and cap w/ o-ring.