This is a Seymour Solar Filter for viewing the Sun with.. The ID is 6" (152mm) and the Polymer Clear Aperture is 5" (127mm)
IT is in Excellent condition and ready for use.. I used it on my Meade 4" telescope. it is barely used as I really never got to use it much.. there are no tears in the filter itself and I believe it was made of Mylar..
Filed under: Eyepieces & Accessories