Thanks to its low profile, the ESATTO 2" is the perfect motorized focuser for Schmidt-Cassegrain telescopes like the 8” and 9.25” Celestron SCT and EdgeHD 800 models. By adding the SC adapter, you can thread the ESATTO 2" focuser directly onto the back of these telescopes, and use the ESATTO to achieve more precise focus, avoiding focus shift and mirror flop by leaving the primary mirror locked (if locks are available). The low profile of the ESATTO leaves you enough back focus to use the the EdgeHD or other SC threaded focal reducers.