Feature: 1. RMS SIZE: The thread interface size complies with the international standard RMS and is compatible with the majority of commercially available professional biological microscopes. 2. SPRING PROTECTION: When in contact with the cover glass while being observed, the lens can automatically rebound, preventing damage to the specimen and the lens. 3. STAINLESS 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. 4. CLEARER IMAGE: This lens has a strong transmittance coating for brighter image and a good refractive index. 5. FINE WORKMANSHIP: Well crafted with fine and smoothly appearance, the lens has a comfortable feel and will not hurt your devices. Specification: Item Type: Achromatic Objective Material: Brass, Stainless Steel Application: Widely used for the thread interface size is an international standard RMS size, and most professional biological microscopes on the market can be used Specification: 40X. Package List: 1 x Lens 1 x Storage Cartridge