The SkyWatcher 90/900 AZ3 Refractor Telescope SW909 is 90mm aperture refractor telescope with a focal length of 900mm. This makes it an excellent telescope for use in stargazing as the longer focal length minimizes chromatic aberrations and increases the overall magnifying power of standard eyepieces. The 90mm aperture provides ample light gathering power to view the most popular celestial bodies and messier catalog objects. It's designed to produce high contrast images with minimal chromatic aberrations. This imaging power comes at a price that is well within the range of most enthusiasts. High Quality Parts and Components Skywatcher uses only high quality components to ensure your telescope delivers sharp images with greatly reduced chromatic aberrations. The included AZ3 mount provides firm support for the optical tube and any imaging equipment you wish to further equip. The mount is sturdy and easy to assemble, so you can spend less time setting up and more time viewing. Features Packed, Great Price Premium optical components and an innovative design allows this refractor telescope to deliver high contrast, bright, and crisp images. Performance and features you would only usually find from higher end premium models.