Bausch and Lomb Supplementary Lens 2X attachment #31-26-19 for the Stereo 1 and 2, StereoZoom 3, 4, 5 series of Bausch and Lomb Stereo Microscopes. It is intended to extend the range of magnification of the Bausch and Lomb stereo microscopes. This lens will double the magnification range. It is in excellent mechanical and cosmetic condition. NOTE: This lens will not work with the Bausch and Lomb stereo 7. Thank you for looking!