Sky-Watcher Skymax-150 PRO (EQ6 PRO) 150mm (6") f/1800 Syn Scan GO-TO Maksutov-Cassegrain Telescope. Black Diamond PRO-Series is the name for the new generation of professional quality telescopes & mounts of the Sky-Watcher range, targeted at the most discerning & critical observers, available in apertures of 150mm & 180mm. Skymax Black Diamond-PRO series Maksutov-Cassegrains are manufactured to extremely high levels of optical & mechanical precision, undergoing very strict quality control procedures & testing by specially assigned technicians, to ensure the highest standards of quality & performance are consistently maintained. They employ super-high contrast optical systems, utilising high-transmission multi-coatings on all optical services, for optimum optical performance. The quality of each telescope is monitored by means of a Ronchi test & an artificial star test. They excel for high-power, high-resolution & planetary applications. No effort is spared to reach optimal optical quality.