The third part of the ramjet is the combustor, also called the combustion chamber. The combustor is where the fuel is introduced to the air, and then burns. Burning fuel adds energy to the air, which will be later used to create thrust. The air must be moving relatively slowly for the combustor to work properly. There is a part inside the combustor called the flame holder. The flame holder, as the name suggests, holds the flame in place. A typical flame holder looks like a ring of small v-shaped pieces of metal. They create little pockets of slow air, which make it easier for the fuel to keep burning.