●Automatic Rebound: Spring protection device, can automatically rebound when touches the cover glass during observation to protect the lens from crushing the specimen ●Brass Material: Made for brass material, fine workmanship, and fall prevention, exquisite and durable, chrome plated accuracy material for the shell ●Clearer: This lens is coated with high light transmittance, with high refractive index, and the image is brighter ●Basic Specifications: This lens has a magnification of 20X, common rail distance of 195mm, and parfocal distance of 45mm ●Wide Application: The screw interface size is the international standard RMS size, which can be used by most professional biological microscopes on the market ●Industrial Supplies Scientific Education Scientific Education Microscope