150 Watt, tungsten Halogen, low voltage without reflectorThe FCS bulb, or HLX 64640, is commonly used in scientific, dental, and medical applications as a microscope light bulb. This bulb is also used in various projector applications. Consumers purchasing FCS bulbs often need them in bulk as consumers often replace bulbs at the same time in their microscopes and other fixtures. Therefore, we pride ourselves are on our great prices for FCS bulb replacements and our even better prices for our quantity discounts to save our customers big.