Brighter and Clearer Lens: Coated lens provides high transmittance and refractive index for brighter, clearer images. Protective Device: The spring protection device automatically retracts when the cover glass encounters the lens during observation, preventing damage to the lens or specimen. Durable Brass Construction: Made from fine brass, this objective lens is corrosion-resistant, durable, and features a chrome-plated shell for precise material integrity. Universal Screw Interface: The international standard RMS size screw interface is compatible with 95% of professional biological microscopes on the market, offering excellent practicality. 40X Magnification: This objective lens provides 40X high magnification, greatly assisting in studies, work, or research. Item Type: Achromatic Microscope Objective Model: 40/0.65 Material: Brass Usage: Microscope Accessories Interface Size: Approx. 20.2 mm / 0.8 in (International Standard RMS Size) Magnification: 40X Numerical Aperture: 0.65 mm Applicable Cover Glass Thickness: 0.17 mm Applicable Microscope Mechanical Tube Length: Approx. 160 mm / 6.3 in Working Distance: Approx. 0.53 mm / 0.02 in Common Rail Distance: Approx. 195 mm / 7.68 in Parfocal Distance: Approx. 45 mm / 1.77 in Spring: Yes (Automatic Rebound) Package Includes: 1 x Lens 1 x Storage Box Customer satisfaction is our top priority. If you encounter any issues with your product after receiving it, such as damage or incorrect quantity, please contact us immediately. We are dedicated to providing the best after-sales service.