This is a 8W fluorescent ring light kit for stereo microscopes. The kit includes one ring light unit with inner diameter 46mm (1-3/4"), one spare ring bulb and a ring adapter with 48mm (1-7/8") thread (in diameter). Using 110V power, it provides cool, even and bright illumination for sharp and clear images. It comes with one year warranty against manufacturing defects. This kit is brand new in original box. Its retail value is above $200.