Special offer buy 12 for just pound697 each a 20 watt cdm tc ceramic metal halide lamp with a g85 base this cdm tc lamp is a compact single ended discharge lamp with a high efficiency cdm tc lamps maintain stable colour over their lifetime and emit a crisp sparkling white light cdm tc lamps are frequently used in shops shop windows public buildings and offices cdm tcs can also be used outdoors for floodlighting and pedestrian areas this lamp is available in colour 830