per William's "Violet Reduction FIlter - 1.25". VR-1 filter threaded to attach to your diagonal on short tube refractors which possess violet and blue false color. This VR filter tremendously decreases violet fringing, it provides good transparency and has a high quality finish." Great for the Orion and other 2 element refractors when trying to take photos. I bought this less than 2 months ago for my Orion 90mm, but I just got a TV Genesis, and now the Orion is just a guide scope, so I no longer need it. New they cost $59 plus
shipping. I'll sell for $45 and I'll pay the conus shipping.
Also willing to trade for a very good 2x barlow or a decent 3x barlow, plus cash either way, depending on the value of the barlow.