Orion 07757 Deluxe Safety Film Solar Filter 6.58 Inch Inside Diameter (Silver) Explore the Sun safely through a telescope with this high-quality solar filter featuring Baader film in a sturdy aluminum cell Fits Orion Space Probe 130 & 130ST, Star Seeker III/IV 130mm, and Celestron Next Star 130ST telescopes Each filter is mounted in a foam-lined, clear-anodized aluminum cell featuring three equidistant securing thumbscrews for secure telescope attachment This filter has an inside diameter of 6.58 inches - it is designed to fit optical tubes with an outer diameter of 6.33 inches to 6.58 inches with included shim materials and securing thumbscrews 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