Feature:1. Clearer Image: This lens is coated with high light transmittance, high refractive index, and brighter image2. Automatic Rebound: Spring protection device, automatically rebound when touches cover glass during observation, protect lens from crushing specimen3. Brass Material: Adopts high quality material, fine workmanship, corrosion and fall prevention, exquisite and durable, chrome plated for shell4. Application: Interface size is the international standard RMS size, can be used by most professional biological microscopes on the market5. Basic Specifications: This lens has 60X magnification, common rail distance of 195mm, and parfocal distance of 45mmSpecification:Item Type: Achromatic ObjectiveModel: 60/0.85Material: BrassUse: Microscope AccessoriesInterface Size: Approx. 20.2mm / 0.80in (International Standard RMS Size)Magnification: 60XNumerical Aperture: Approx. 0.85mm / 0.03inCover Glass Applicable Thickness: Approx. 0.17mm / 0.007inMicroscope Applicable Mechanical Tube Length: Approx. 160mm / 6.30inWorking Distance: Approx. 0.53mm / 0.02inCommon Rail Distance: Approx. 195mm / 7.68inParfocal Distance: Approx. 45mm / 1.77inSpring: Yes (Automatic Rebound).Package List:1 x Achromatic Objective1 x Storage Box