Only tested on the Moon so far but I am very impressed with the optics and general finish overall, especially at this price point. Used with a Evostar 150 mm f/8 Acromat Refractor and Baader Hyperion zoom eyepiece on 24mm setting I had lovely crisp and not too dim views of Crater Tycho and mountains and valleys at the terminator. The Barlow itself is very nicely made with a heavy and chunky feel to it, the optics show a nice greenish tinge from the multi-coating. It comes in a very nice padded box too. As always the usual excellent service from FLO, Thank you