This telescope is an 6" f/9 Astro-Physics APO refractor. Of the three basic types of telescopes ( refractor, reflector, catadioptic), the APO refractor is the most treasured by both astrophotographers and visual observers. These instruments produce pinpoint sharp images with very high contrast. They are also very difficult and expensive to produce. Today, there here are only two companies in the world that manufacture this type of telescope on a commercial basis: Astro-Physics (USA) and Takahashi (Japan). I obtained this treasure as well as a superb Takahashi refractor in a serendipity trade from my BMW K75RT Motorcycle .