Orion 07737 6.58-Inch ID Full Aperture Glass Telescope Solar Filter (Silver) A must-have white-light filter for safe observation of the Sun and sunspots without damaging your eyes Optical glass filter fits snugly over your telescope's aperture to block 99.99 percent of incoming sunlight so you can view safely Glass filter elements are machine-polished and triple-coated with nickel-chromium stainless steel Each Orion telescope solar filter includes three equidistant thumbscrews, 4x 1/16 inch thick adhesive foam tabs, and 4x 1/8 inch thick adhesive foam tabs for customized friction fit to your telescope Note: All Orion solar filters are designed for use with an adequate friction fit attachment. Thumbscrews should ONLY be used to keep filter securely in place once a friction fit has been achieved