Features: Made of high quality all-steel material, it is durable and hard to wear. The magnification is adjustable and the image is clear, making it easy to observe the texture and structure of tiny things. There are six objective lenses available, 4X, 10X, 20X, 40X, 60X, 100X. Each objective is equipped with a single plastic box for easy storage. This product is dedicated to a variety of biological microscopes, using a Standard RMS interface 20.2mm. Specifications: Condition: 100% Brand New Material: Steel Sta ndard: Standard RMS interface 20.2mm Type: 4X, 10X, 20X, 40X, 60X, 100X Achromatic Objective Lens (Optional) Magnification Numerical aperture Working distance Thickness of the coverslip Impregnating medium Spring 4X 0.1mm 18mm 0.17mm No No 10X 0.25mm 7mm 0.17mm No No 20X 0.4mm 0.55mm 0.17mm No Yes 40X 0.65mm 0.53mm 0.17mm No Yes 60X 0.65mm 0.13mm 0.17mm No Yes 100X 1.25mm 0.13mm 0.17mm Oil Yes The use of various objectives: 4X: Observe insects, banknotes, repair electronic motherboards, etc. (can be viewed separately), and the imaging is clearer than the magnifying glass. 10X: Repairing fine electronic components, small antiques, etc. (can be viewed separately), the imaging is clearer than the magnifying glass. 20X: Observe aphids, aquatic products, silkworms, etc. 40X: Observe cells, sperm, eggs, artificial insemination, etc. 60X: Observe cells, sperm, eggs, artificial insemination, crude bacteria, etc. 100X: Observe medical tests, blood tests, bacteria, scientific research, students see specimens, etc. Package list: 1 * Achromatic Objective Lens .