Solar filter - fits over an 8 inch telescope. I bought this second hand many years ago and didn’t use it on my telescope. Last time it saw service was with binoculars to view the transit of Venus back in 2012.
It could do with a clean with isopropyl but otherwise is in good condition. It’s ancient - the instructions refer to taking images of the sun using “very fine grain films”!
From memory it cost me around $250. I’ll take $50 with the buyer paying shipping.
