The Spectrum 5" Full Aperture Film Solar Filter- 117mm to 124mm is a premium quality polymer film filter meant for safe and comfortable solar astronomy, both imaging and visual. These economically designed filters provide natural, high clarity solar views for your persual and use when used with an appropriately sized telescope. They are made with high quality polymer film combined with high reflectivity coatings. The Spectrum 5" Full Aperture Film Solar Filter- 117mm to 124mm is sized with an O.D. Measurement of 117mm to 124mm, leaving it the perfect size for use with ANY of the following telescopes: Celestron's Firstscope 76, Nexstar 4/4SE, C4, and 102HD models. Meade's ETX 105, DSX 102, and 2045 Models. Stellarvue's SV102ED, Skywatchers 80ED and Evostar 80ED, Questars 4.75, the Takahashi FSQ-106, Tele-Vue's 101 and 102 models, and the Vixen VMC 110L.