Feature: 1. STANDARD SIZE: This objective lens has universal 20.2mm standard RMS interface thread, suitable for most biological microscopes, has good compatibility. 2. CLEAR IMAGING: This infinite objective lens has a clearer and sharper image, and a wider field of view than a regular achromatic objective lens. 3. PARALLEL BEAM: The infinite objective lens is parallel optical beam, with no included angles, correction of spherical and sunken errors, has accurate imaging. 4. COATING FILM LENS: The 4X objective lens is coated, has high transmittance and refractive index, making it less prone to scratches, fragmentation, or wear. 5. METAL STRUCTURE: The microscope objective lens is made of excellent brass and stainless steel, wear and oxidation resistance, have a longer service life. Specification: Item Type: Objective Lens Material: Brass, Stainless Steel Use: International standard RMS size thread interface, suitable for most professional biological microscopes on the market Specification: 4X. Package List: 1 x Objective Lens1 x Storage Cylinder