 Orion sells a range of telescopes that they characterize as "beginner", "intermediate" or "advanced", including Newtonians, Maksutovs, Schmidt-Cassegrains, Ritchey-Chrétiens and refractors with or without (sold as optical tube assemblies or "OTA") a variety of mounts.Orion also sells a series of Dobsonian telescopes that come in "Classic" and "IntelliScope" versions, the latter with upgraded accessories and the ability to indicate astronomical objects to the observer aided by a computerized object database.Orion also sells Dobsonians with GoTo and tracking capabilities.