Most of Celestron’s Schmidt Cassegrain and EdgeHD optical tubes are Fastar compatible. Some optical tubes will have a Fastar logo on the secondary mirror cell assembly (or housing) and some do not though you will be able to tell if you are able to unscrew the secondary mirror retaining ring.

Here is a list of Celestron Fastar compatible telescopes and optical tubes:

 

Optical Tubes
Schmidt Cassegrain 14” Schmidt Cassegrain 11” Schmidt Cassegrain 9.25” Schmidt Cassegrain 8” Schmidt Cassegrain 6”	EdgeHD 14” EdgeHD 11” EdgeHD 9.25” EdgeHD 8”

 

Telescopes
CGX-L Series CGX Series CPC and CPC Deluxe Series CGEM II Series	NexStar Evolution Series NexStar 6SE and 8SE SkyProdigy 6 Advanced VX (6” - 11” Schmidt Cassegrain and 8" EdgeHD models)