This is a set of 4 plan-fluor objective lenses for high-resolution biological and fluorescence applications. The set includes 4X, 10X, 40X, and 100X lenses. Semi-apochromatic optical corrections improve resolution and color accuracy by realigning blue, green, and red wavelengths. Plan field corrections further improve image quality by providing edge-to-edge sharpness. Along with improvements in resolution, the optics provide better transmittance in the ultraviolet and near-infrared bands for use in fluorescence microscopy. The lens is designed for use with AmScope upright, infinity-corrected microscopes, as well as other microscopes using RMS mounts and 45mm parfocal distance. Compatibility Optical System Infinite Reference Focal Length 180mm Mounting Thread RMS 20.32mm Parfocal Distance 45mm Lens Specifications Magnification Corrections NA Working Distance Cover-glass Thickness Immersion Medium Nosecone 4X Plan, semi-apochromatic 0.13 16.3mm — — Fixed 10X Plan, semi-apochromatic 0.30 12.4mm 0.17 — Fixed 40X Plan, semi-apochromatic 0.75 0.35mm 0.17mm — Spring 100X Plan, semi-apochromatic 1.30 0.13 0.17mm Oil Spring