Feature: 1. BRASS, STAINLESS STEEL MATERIAL: Made of premium brass and stainless steel material, these lens are anti corrosion and anti drop, exquisite and durable, with chrome plated accuracy material on the shell. 2. SPRING PROTECTION DEVICE: When observing, contact with the cover glass, the lens can automatically rebound, protecting the lens from damaging the specimen. 3. RMS SIZE: The thread interface size is an international standard RMS size, and most professional biological microscopes on the market can be used. 4. CLEARER IMAGE: These lens are coated with strong transmittance film, with high refractive index and brighter imaging. 5. 4 LENS: There are 4 pcs lens, 4X 10X 40X 100X, you can use them respectively to meet your different needs. 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: 4X 10X 40X 100X. Package List: 4 x Lens 4 x Storage Tube Note: Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.