Having the Spectra 72 transmitter frequency synthesizer module in your Optic 6, Eclipse or Prism radio is like having 50 perfectly tuned modules in your pocket. The powerful feeling of being able to transmit on any of the fifty, 72MHz channels is fantastic. Just adjust the Spectra module with the small plastic screwdriver and switch the crystal in your receiver to match, and your ready to fly on any channel you choose. No one but Hitec offers such versatility at such a low price, check it out at your hobby dealer today!