The National 760-160P 60xR Retractable Plan Achromat Objective Lens is for use with the 160 and 165 microscope series. It features a 0.90 numerical aperture and 60x magnification. A retractable objective lens provides additional protection against lens or slide damage. The lens also features a planar achromatic design, providing a flat field and correction for color and spherical aberration.