The NichoLED LED Spot Illuminator is a direct replacement for the B&L / Leica Nicholas halogen illuminators that have been discontinued for quite a few years. These are very bright and feature a single on/off/intensity knob and a rugged metal housing. There are many B&L Stereozoom microscopes still in use, and the NichoLED illuminator is a great way to bring them into the 21st century. Also works as a replacement for American Optical / Reichert model 650 illuminators for AO Cycloptic and AO 569/570 zoom stereos.