AmScope LED-144W-ZK White Adjustable 144 LED Ring Light Illuminator for Stereo Microscope & Camera Provides intense and focused shadow-free illumination 2.5" (62.5mm) inside and 3.64" (92.5mm) overall outside diameters Power input: 110-240V, 50-60HZ, auto switching 1-7/8" (48 mm in diameter) ring adapter included