I have a Futaba 9-C and I still have a Spectra from my old Hitec 7 that workes in it. You just flip it upside down and it fits the Futaba. Years ago I used this crystal because I had so many planes on different channels, today I locked into just one so I no longer use the Spectra except for when I am setting up someone elses plane for them when I do there build. I just get there controls all at nutral so I can make up there control rods. Spectra works pretty well but when it was being used a lot we called it Dial A Crash because people forgot to retune them for there other planes and wouldn't figure this out until after take off. It never happened to me but I have seen it happen a couple of times to others. One of those things you just have to be careful about!!!