From what I know off Skymasters Facebook, C, D version in the Classic Hornet, E,F in the Superhornet. Superhornet is comming out first, Classic C & D Version will be slightly later this year. John mentioned Winter(not sure which hemisphere) for that version. Test Version of the Superhornet flew on a single K170. Both Versions are up on the Skymaster Web page minus prices showing schemes. Personally I want the C version. Looking forward to it.