This is a 64-LED intensity & direction adjustable ring light with mounting size up to 2-1/2" (64mm) in diameter. The light ring is consisted of 4 portions. You can turn on/off each portion of the ring light separately so that you can control the light direction. The ring light has 2-1/2" (64mm) inside and 4" (100mm) outside diameters. It works with power supplies from a 110-220V 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, especially for gemological, coin and gem/jewelry microscopes. This kit comes with one year warranty against manufacturing defects. It is brand new in original box. Features & Specifications: 64 bright white LED bulbs Adjuastable light directions Variable intensity control Intense and focused shadow-free illumination 100,000 hours of life Power input: 110-240V, 50-60HZ, auto switching Fits up to 2-1/2" (64mm) mount rings Inside diameter of the ring light: 2-1/2" (64mm) Outside diameter of the ring light: 4" (100mm) Packing List: One 64-LED Ring Light One Control Box One Power Cable One 48mm Ring Adapter