Features: 1.Dimensions: The internal diameter of this adapter ring is 50mm / 2in, outer diameter is 80mm / 3.1in and the working diameter is 76mm / 3in. 2.Application: Microscope camera adapter ring is suitable for 120X 180X 300X monocular C mount lens with working diameter of 50mm. 3.Main Function: If you have a stereo microscope, this lens ring adapter can help to turn your stereo microscope to video microscope. 4.Aluminum Alloy Material: Lens ring adapter is made of high strength aluminum alloy, with good durability and stability, not easy to rust and deform. 5.Long Lasting: Exquisite workmanship, microscope monocular lens ring adapter has stable and reliable performance, with long service life. Specification: Item Type: Microscope Ring Adapter_x000D_ Material: Aluminum Alloy_x000D_ Internal Diameter: Approx. 50mm / 2in_x000D_ Outer Diameter: Approx. 80mm / 3.1in_x000D_ Working Diameter: Approx. 76mm / 3in PackageList: 1 x_x000D_ _x000D_ MicroscopeRingAdapter 1 x Hex Wrench