CERAMIC METAL HALIDE
A Ceramic Metal-Halide lamp (CMH), also generically known as a Ceramic Discharge Metal-Halide (CDM) lamp, is a type of Metal-Halide lamp that is 10–20% more efficient than the traditional quartz Metal Halide and produces a superior colour rendition (80-96 CRI).
Applications for these lamps include shop lighting, street lighting, architectural lighting and agricultural lighting including grow lights. A CMH light was first exhibited by the Thorn Lighting Group in 1981 at the Hannover World Light Fair, and the first commercial Ceramic Metal Halide lamps were distributed by Philips in 1994.
The term "Light Emitting Ceramic" (LEC) is sometimes generically used to describe Ceramic Metal-Halide lamps in grow lights in general, though that term is actually the registered trademark of a specific brand of Ceramic Metal Halide light.