Welcome to our store! Experience clearer images: This lens is coated for high light transmission and features a high refractive index, resulting in brighter images. Automatic Rebound: Equipped with a spring protection device, it automatically rebounds when touching the coverslip during observation, protecting the lens from crushing the sample. Premium Brass Material: Crafted from high-quality brass with fine workmanship, this lens is corrosion-resistant, drop-proof, exquisite, and durable. The shell is made of precision chrome-plated material. Wide Application: The screw interface size conforms to the international standard RMS size, making it compatible with most professional biological microscopes on the market. Key Specifications: This objective lens has a magnification of 20X, a common rail distance of 195mm, and a parfocal distance of 45mm. Item Type: Achromatic Objective Model: 20/0.40 Material: Brass Usage: Microscope Accessories Interface Size: Approx. 20.2mm / 0.80in (International Standard RMS Size) Magnification: 20X Numerical Aperture: Approx. 0.40mm / 0.02in Coverslip Applicable Thickness: Approx. 0.17mm / 0.006in Microscope Applicable Mechanical Tube Length: Approx. 160mm / 6.30in Working Distance: Approx. 0.55mm / 0.02in Common Rail Distance: Approx. 195mm / 7.68in Parfocal Distance: Approx. 45mm / 1.77in Spring: Yes (Automatic Rebound) Package Includes: 1 x Achromatic Microscope Objective, 1 x Storage Box Customer satisfaction is our top priority. If you encounter any issues with your product upon receipt, such as damage or incorrect quantity, please contact us immediately. We are committed to providing you with the best after-sales service.