DescriptionAdopting great quality material, which lets you use it for a very long time. Though it is simple in design, it's so practical when you use it. The excellent workmanship of our product will bring you a good experience. Easy and convenient to install and use, it is a very useful achromatic objective lens.Features- Color: Silver.- Size: 6.00X4.00X4.00cm/2.36X1.57X1.57 inch.- Material: Steel.- Magnification: 4X.- Cover glass Thickness: 0.17mm.- Working distance: 18mm.- Mounting size: 20.2mmstandard RMS thread).- Numerical aperture: 0.1mm.- Made of material for a long time and durable use.- Smooth surface and nice polished, neat and generous, so don't need to worry about harming your hand.- Steel shell is precision machined, stable and durable for long time use.- This is a achromatic objective lens for biological microscope.- Increase contrast: It can eliminate unwanted reflections and increase contrast.Packing list: 1 x objective lens