This is a 56-LED ring light with built-in intensity control and mounting size up to 2-3/8" (60mm) in diameter. The ring light has 2-3/8" (60mm) inside and 4" (100mm) outside diameters. It works with power supplies from 110V to 240V. It comes with a 1-7/8" (48mm 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 microscopes. This kit comes with one year warranty against manufacturing defects. It is brand new in original box.