This is a 144-LED intensity adjustable ring light for stereo microscopes with a mounting size 2.4" (61mm) in diameter. The ring light has 2.5" (62.5mm) inside and 3.64" (92.5mm) overall outside diameters. It works with power supplies from a 100-240V and comes with a 1-7/8" (48 mm in diameter) ring adapter. With variable intensity control, it provides cool, even, intense, and focused shadow-free illumination. It is an ideal durable cool light source for all stereo microscopes. This kit comes with one year **against manufacturing defects.