Feature 1RMS SIZE: The thread interface size complies with the international standard RMS and is compatible with the majority of commercially available professional biological microscopes. 2SPRING PROTECTION: When in contact with the cover glass while being observed, the lens can automatically rebound, preventing damage to the specimen and the lens. 3STAINLESS STEEL, BRASS MATERIAL: Achromatic objective is made of premium brass and stainless steel material, are long lasting, and chrome plated on the shell. They are also anti corrosion and anti drop. 4CLEARER IMAGE: This lens has a strong transmittance coating for brighter image and a good refractive index. 5FINE WORKMANSHIP: Well crafted with fine and smoothly appearance, the lens has a comfortable feel and will not hurt your devices.Item Type: Achromatic ObjectiveMaterial: Brass, Stainless SteelApplication: Widely used for the thread interface size is an international standard RMS size, and most professional biological microscopes on the market can be usedSpecification: 40X .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List1 x Lens1 x Storage Cartridge