Item Type: Achromatic Microscope Objective_x000D_Model: 4/0.10_x000D_Material: Copper_x000D_Use: Microscope accessories_x000D_Interface Size: Approx. 20.2mm / 0.8in (international standard RMS size)_x000D_Magnification: 4X_x000D_Numerical Hole Diameter: 0.10mm_x000D_Cover Glass Applicable Thickness: 0.17mm_x000D_Microscope Applicable Mechanical Tube Length: Approx. 160mm / 6.3in_x000D_Working Distance: Approx. 18mm / 0.71in_x000D_Common Rail Distance: Approx. 195mm / 7.68in_x000D_Parfocal Distance: Approx. 45mm / 1.77in 1BRIGHTER AND CLEARER IMAGE: Lens after coating bring high transmittance, high refractive index, the image is brighter and clearer 2CORROSION 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 materials 3STANDARD 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 market 44X MAGNIFICATION: This is a 4X high magnification objective, helps a lot in study, work or research, useful and practical 5CORROSION RESISTANT LENS: Achromatic microscope objective bring more comfortable viewing, lenses will not corrode, be dazzled, and have a long service life 1 x Lens 1 x Storage Box