Features High Light Transmittance and Refractive Index: The lens is coated with high light transmittance and high refractive index, providing brighter and clearer images. Standard and Universal: The screw interface size is the international standard RMS size, compatible with 95% of professional biological microscopes on the market. Brass Material: Microscope objective lens made of brass material with fine craftsmanship, offering corrosion resistance and durability. Chrome Plated Shell: The microscope objective shell is chrome plated, ensuring stability and long-term use. Application: This microscope objective is an essential component for laboratory microscopes, primarily used for magnification to observe specimens. Specification: Item Type: Achromatic Microscope Objective Material: Brass Model: 4/0.10 Use: Microscope Accessories Interface Size: Approx. 20.2mm / 0.8in (International standard RMS size) Magnification: 4X Numerical Aperture: 0.10 Cover Glass Applicable Thickness: 0.17mm Microscope Applicable Mechanical Tube Length: 160mm / 6.3in Working Distance: 13mm Common Rail Distance: 195mm / 7.7in Parfocal Distance: 45mm / 1.8in Package List: 1 x Achromatic Microscope Objective 1 x Storage Bottle