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 **against manufacturing defects. This kit is brand new in original box. Its retail value is above $200.