AmScope LED-64-A Microscope Ring Light Illuminator, Stereo Microscope LED Ring Light with Dimmer, 9W 90V-260V 64-LED 64-LED Ring light provides strong shadow free illumination Comes with a control box for light intensity adjustment 1.77" (45mm) I.D. and 3.35" (85mm) O.D. Mounting size: up to 2.4" (61mm) in diameter Wide band voltage power supplies: 100V to 240V