Feature:1. BRIGHTER AND CLEARER IMAGE: Lens after coating bring high transmittance, high refractive index, the image is brighter and clearer2. CORROSION RESISTANT AND DURABLE: Copper material with fine workmanship, corrosion resistant and not easy to fall, exquisite and durable, the shell is chrome plated with accurate materials3. STANDARD SCREW INTERFACE SIZE: The screw interface size is the international standard RMS size, which can be used by 95% of professional biological microscopes on the market4. 4X MAGNIFICATION: This is a 4X high magnification objective, helps a lot in study, work or research, useful and practical5. CORROSION RESISTANT LENS: Achromatic microscope objective bring more comfortable viewing, lenses will not corrode, be dazzled, and have a long service lifeSpecification:Item Type: Achromatic Microscope ObjectiveModel: 4/0.10Material: CopperUse: Microscope accessoriesInterface Size: Approx. 20.2mm / 0.8in (international standard RMS size)Magnification: 4XNumerical Hole Diameter: 0.10mmCover Glass Applicable Thickness: 0.17mmMicroscope Applicable Mechanical Tube Length: Approx. 160mm / 6.3inWorking Distance: Approx. 18mm / 0.71inCommon Rail Distance: Approx. 195mm / 7.68inParfocal Distance: Approx. 45mm / 1.77in.Package List:1 x Lens1 x Storage Box