Adjustable Brightness]Compact design with built-in dimmer. 0-100% adjustable brightness. Best Working Distance: 2"-10"(50~250MM) Adjustable Mounting Diameter]Adjustable screws to fix the light onto microsocpe. Max mounting diameter 2.5"(63mm) inside. Suitable for various microscopes and cameras 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. Less Heat] High Light Efficiency. Low temperature to maximize the user's comfort and operation, even for a long period 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., Manufacturer: PokFhgur