This is a brand new 2X Barlow (auxiliary objective) lens for stereo/industrial microscopes. Give your microscope a boost with greater power & clarity at a fraction of cost. It doubles the magnification power of the microscopes, while decreasing the field of view and working distance. This lens comes with a 1-7/8" (48mm) mounting thread and goes with WP-1F/WP-2F/WP-3F/WP-5F/WP-7F/WP-8F/WP-9F series stereo/industrial microscopes.