These products work very well with my existing equipment, and arrived promptly. Great bang for your buck!
Dear sirs, I bought throught amazon Helios Solar Glass Filter 12.5" (317mm). Fits Optical Tube Diameter 12 1/8" (308mm) to 12 3/8" (314mm). SF1250, fit it's perfect to my CGEM Celestron 11", excelente product