Takahashi 2" Visual Adapter - TKT37110
Takahashi Short 2" Visual Adapter
This 50.8mm Eyepiece Holder is #70S on the FSQ-106EDX4 Visual Chart. It is shown threading into the 8L Coupling (included with your scope) on one side, and accepting a variety of adapters and/or accessories on the other to do visual observations or photography with your scope.
The Takahashi TKP27110S was originally designed for the shorter Sky 90, but also works with the FSQ-85 and the FSQ-106EDX when certain 50.8mm accessories come after it, such as the Extender QE, the Takahashi TET0002 or 2L Extension Tubes, a 2" diagonal mirror, etc.