Features 1、Clearer Image: This lens is coated with high light transmittance, with high refractive index, and the image is brighter 2、Automatic Rebound: Spring protection device, automatically rebound when touches the cover glass during observation to protect lens to avoid crushing specimen 3、Brass Material: Made for brass material, fine workmanship, corrosion and fall prevention, exquisite and durable, chrome plated accuracy material for shell 4、Wide Application: Screw interface size is the international standard RMS size, can be used by most professional biological microscopes on the market 5、Basic Specifications: This lens has magnification of 100X, common rail distance of 195mm, and parfocal distance of 45mm Specification Item Type: Achromatic Objective Model: 100/1.25 Material: Brass Use: Microscope Accessories Interface Size: Approx. 20.2mm / 0.80in (International Standard RMS Size) Magnification: 100X Numerical Aperture: Approx. 1.25mm Cover Glass Applicable Thickness: Approx. 0.17mm / 0.007in Microscope Applicable Mechanical Tube Length: Approx. 160mm / 6.30in Working Distance: Approx. 0.13mm / 0.005in Common Rail Distance: Approx. 195mm / 7.68in Parfocal Distance: Approx. 45mm / 1.77in Impregnation Medium: Cedar Oil (OIL) Spring: Yes (Automatic Rebound) Package List 1 x Achromatic Objective 1 x Storage Box