This will not be the technical report that is desired, but Venus and the moon looked so much better during the brief "first light" that I did not regret my purchase. This is the most expensive accessory that I have purchased, so the above statement is a sincere recommendation.

To me, it seems to be a simple device that lets you see more detail with the equipment you use regularly.

It was used with a BO 1278 and compared to a quality diagonal with a WO minus violet filter. I was impressed.