This is a 72-LED intensity direction adjustable ring light with mounting size up to 2.3" (60mm) in diameter. The light ring consists of 4 individual portions (4 lighting zones) that can be turned on/off separately. You may use the feature to change lighting directions and obtain the best illumination for your application. The ring light has 2.3" (60mm) inside and 4" (102mm) 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 **against manufacturing defects. Features Specifications :72 bright white LED bulbsLighting direction changeableVariable intensity controlIntense and focused shadow-free illumination100,000 hours of lifePower input: 110-240V, 50-60HZ, auto switchingFits up to 2-1/2" (64mm) mount ringsInside diameter of the ring light: 2.3" (60mm) Outside diameter of the ring light: 4" (102mm) Packing List :One 72-LED Ring Light (B)One Power CableOne 48mm Ring AdapterShipping Weight: 3 lbs