The Focus Motor for SCT & EdgeHD provides electronic focusing for Celestron Schmidt-Cassegrain (SCT) and EdgeHD telescope optical tubes With the focus motor installed you can bring celestial objects into sharp precise focus using your telescope's hand controller or a computer instead of using the focuser knob A focus motor is great for visual observers who want to dial in exact focus (especially those with dexterity issues) and a must-have accessory for astroimagers With a motorized focuser installed an astroimager no longer needs to be physically near the telescope to focus an image Combined with computerized control of the mount and camera the focus motor enables the imager to gather data remotely from a backyard observatory or even a telescope located hundreds of miles away As an added bonus port covers protect the ports while not in use and the covers cannot be lost due to the tethered design The focus motor is compatible with all SCTs from 6” to 14” in aperture that have been produced since the year 2006 It is not compatible with 5” SCTs or older models It is compatible with the 8” Rowe-Ackermann Schmidt Astrograph (RASA) the 36cm RASA the 7” Maksutov-Cassegrain and all the EdgeHD optical tubes It can also be used with the 11” RASA but requires the Focuser Retrofit Kit for RASA 11 For 6” Schmidt-Cassegrain telescopes only the Off-Axis Guider (#93648) cannot be used when the focus motor is installed due to mechanical interferences There are three options for powering your Celestron Focus Motor 1 When using a Celestron computerized mount you can power and control the focus motor through the mount using the supplied AUX cable This allows control from the mount's hand controller (NexStar+ or StarSense) or a computer 2 If you are not using a Celestron mount you can power and control the focus motor from a computer USB port You will need a user supplied USB A-to-B cable 3 You may also opt to use an external 12V DC power source which plugs into the motor's power jack