Water drips from a tank above the Carbide, which produces acetylene gas. A valve in the water tank controls how much water drips into the Carbide. This also causes pressure to build up so the acetylene gas is forced through a felt filter pad and into a jet so a small, very bright flame is produced at the jet. Control of the flame size is via the drip valve. Once you get the hang of operating the light it's easy set it up and operate. As long as the jet is clean, felt filter pad is dry and clean, and the rubber seals are good to prevent gas from exiting anywhere except through the jet, the light will function properly. When finished with a carbide light you simply cut off the water supply to the carbide and blow out the flame. After the lamp cools clean out the carbide and dispose of properly, dump any remaining water; remove the felt pad, clean it by rinsing it with clean water and let it dry, clean the rubber seals and coat them with Armor All rubber preservative.