Sky-Watcher Skymax-127, 127mm (5"") f/1500 Maksutov-Cassegrain Optical Tube Assembly. Skymax Black Diamond Series Maksutov-Cassegrains. Available in apertures of 127mm, 150mm and 180mm. Excel for high-power, high-resolution and Planetary applications. 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 and an artificial star test. No effort is spared to reach optimal optical quality. Please note, the is an Optical Tube Assembly only, mount and tripod are available separately.