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 & 180mm. Excel for high-power, high-resolution & 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 & an artificial star test. No effort is spared to reach optimal optical quality. Please note, the is an Optical Tube Assembly only, mount & tripod are available separately.