10x / 0.25 n.a. infinity corrected universal lens (numerical aperture of 0.25). L.W.D. (Long Working Distance) targets with high working distance. fully coated lenses with high color correction. Flat-field correction lens construction, RMS (20.2mm) threaded objective mount, Tension-free objectives specially designed for microscope with metallurgical polarization, high light transmission. Great build quality.