Fangrui Product Details : For Industrial Microscope Camera C Mount Lens 1-3/4inch (42mm) Mounting Thread Doubling Total Magnification Power Of Your Microscope And Reduce The Focus Length Purpose: They Are Additional Accessories That Increase The Working Distance Of The Microscope Or Increase The Magnification Of The Microscope. They Provide Clear Images; They Are Suitable For Optical Monocular Lenses With 42mm Threaded Interfaces. Suitable For Video Microscopy. Purpose: 0.5x Reduction Objective Lens To Increase Working Distance. Auxiliary Large Objective Lenses Such As 0.5x Are Suitable For 10a Monocular Video Microscopes. Magnification Power: 0.5x Objective Magnification Power By 0.7 - 4.5x (about 10 - 180x On The Display, Using 0.5x Barlow Lens About 2.45 - 360x On The Display) Tips: The Product May Be Updated Constantly, The Actual Product May Have Slight Differences Or Color Differences The Color And Appearance May Be Changed, Please Dont Mind. And Take A Consideration Before Place The Order If You Have Request For