Pictured here is the second generation of Active Optics (AO) from Starlight Xpress. This particular unit was designed specifically for use with QSI cameras. Attached to the AO unit is a QSI 683wsg camera. br/The AO is a high-performance tracking system that yields wonderfully round stars with long focal length telescopes such as my SkyWatcher SkyMax 127 Maksutov-Cassegrain or my 10-inch TPO Ritchey-Chretien reflector.br/I now own the third generation AO unit which features USB connectivity directly to my Starlight Xpress Trius 694 camera. Combined, they make for a powerful imaging system.