1,Clearer: This lens is coated with high light transmittance, with high refractive index, and the image is brighter 2,Automatic Rebound: Spring protection device, can automatically rebound when touches the cover glass during observation to protect the lens from crushing the specimen 3,Brass Material: Made for brass material, fine workmanship, corrosion and fall prevention, exquisite and durable, chrome plated accuracy material for the shell 4,Wide Application: The screw interface size is the international standard RMS size, which can be used by most professional biological microscopes on the market 5,Basic Specifications: This lens has a magnification of 20X, common rail distance of 195mm, and parfocal distance of 45mm Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.