If you are searching for the most precise motorized focuser to use the GSO/Orion/TPO Ritchey-Chretien 152mm f/9 or 203mm f/8 (both aluminum and carbon tubes) for astrophotography, this adapter allows you to connect ESATTO 2" to this telescope. You can use the standard extensions that come with the RC telescope in order to install the focuser at a precise distance from the OTA. Based on the camera and accessories train you want to connect, you may need extenders to reach the focus with your camera.