Did you check on Horizon's site?

I did, and here's what is says on the Vapor.
Compatible with any Spektrum™ DSM2™ transmitter, the Vapor® is an innovative Ultra-Micro™ Bind-N-Fly™ plane that offers pilots a one-of-a-kind indoor experience. As ParkZone’s slowest and lightest fixed-wing aircraft, it can be flown almost anywhere—a living room, a basement, even a conference room at work. Incredibly compact and loaded with all of RC’s best innovations, owners of DSM2 transmitters (including the DSM2 radio utilized by E-flite’s Blade® CX2) can have the Vapor airborne in no time, making it the perfect alternative for those times when you can’t make it out to a park or flying field.


Now then there's this also. Again from Horizon's site, on the Vapor.
Compatible with all transmitters using DSM2™ technology

And don't miss this from Horizon's site again, on the Blade CX2
The Spektrum AR6100e receiver installed on your model weighs just 4.4-grams and is compatible with the included E-flite LP5DSM transmitter and other Spektrum DSM2 equipped transmitters and modules. Please visit the AR6100e (SPMAR6100E) product page on www.SpektrumRC.com or www.HorizonHobby.com for more information regarding this receiver’s features and functions


Sometimes the answer is right there if you look for it, especially at the mfg site, especially Horizon.

Happy flying.