Welcome to our store! 1、BRIGHTER AND CLEARER IMAGE: Lens after coating provides high transmittance, high refractive index, the image is brighter and clearer 2、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 precise materials 3、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 market 4、4X MAGNIFICATION: This is a 4X high magnification objective lens, helps a lot in studies, work or research, useful and practical 5、CORROSION RESISTANT LENS: Achromatic microscope objective lens provides more comfortable viewing, lenses will not corrode, be dazzled and have a long service life Item Type: Achromatic Microscope Objective Model: 4/0.10 Material: Copper Use: Microscope accessories Interface Size: Approx. 20.2mm / 0.8in (international standard RMS size) Magnification: 4X Numerical Aperture: 0.10mm Cover Glass Applicable Thickness: 0.17mm Microscope Applicable Mechanical Tube Length: Approx. 160mm / 6.3in Working Distance: Approx. 18mm / 0.71in Common Rail Distance: Approx. 195mm / 7.68in Parfocal Distance: Approx. 45mm / 1.77in 1 x Lens 1 x Storage Box Customers are our top priority. If you discover any problems with your product after receiving it, such as damage or incorrect quantity, please contact us immediately. We strive to provide you with the best after-sales service.