Adjustable Mounting Diameter]Adjustable screws to fix the light onto microsocpe. Max mounting diameter 2.5"(63mm) inside. Suitable for microscopes and cameras Adjustable Brightness]Compact design with built-in dimmer. 0-100% adjustable brightness. Best Working Distance: 2"-10"(50~250MM) Less Heat] High Light Efficiency. Low temperature to maximize the user's comfort and operation, even for a long period Input Voltage and Power Source: Operates on a USB DC 5V input, allowing for convenient power access through standard USB ports, which is ideal for diverse working environments. Wide Applications]1-7/8" (48 mm in diameter) ring adapter included, suits for 99% stereo microscopes. Suitable for Stereo Microscopes, Cameras, Zoom Magnification etc. I. Mount LED chips, available in cool white and warm white light; II. Input Voltage: 100-250V power adapter or 5V USB socket; III. Power: 3-5W IV. Brightness Adjustment: 0-100% V. Working Distance: 20-160 mm VI. Mounting Interface: Φ30-Φ65mm VII. Operating Temperature: -20 ~ +40℃ Color: As Shown Material: plastic Package Contents: 1*LED Ring Light Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.