This is an intensity-adjustable 64-LED ring light with control box. Its mounting size is up to 2-1/2" (64mm) in diameter. The ring light has 2-1/2" (64mm) 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. This ring light 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. Features & Specifications: 64 bright white LED bulbs 100,000 hours of life Intense and focused shadow-free illumination Variable intensity control Inside diameter of ring light: 2-1/2" (64mm) Outside diameter of ring light: 4 (100mm) Power input: 110-240V, 50-60HZ, auto switching Fits up to 2-1/2" (64mm) mount rings Packing List: One 64-LED Ring Light One Control Box One Power Cable One 48mm Ring Adapter