The hydrogen discharge lamp was water cooled. It is a type of high-intensity discharge (HID) gas discharge lamp. The dihelium excimer is an important component in the helium discharge lamp. Intensity control was provided via a mechanical shutter (the discharge lamp being non-dimmable). The VL5 Arc introduced a 575W discharge lamp to the design. A neon lamp (also neon glow lamp) is a miniature gas discharge lamp. The light source was a 35W discharge lamp, powered from an internal supply. A small discharge lamp containing a bi-metallic switch is used to start a fluorescent lamp.