I purchased this a while back intending to use it in a dob that needed such mirror. I had the mirror tested and it tested not quite 1/4 wave. It would be sufficient for a light bucket. Also as shown in the photo there is one small subsurface clamshell on one edge. It would go under one of the mirror clips and is of no significance. I have decided to sell it as is to a buyer that would want to do the very little work of finishing figuring the surface. Selling as is for less than the price of a pyrex blank. The pyrex glass is full thickness and full diameter.
Filed under: Eyepieces & Accessories