Except, they don’t tell you what you get! Or what else you might need or want. Tacx is bad about the “add-ons”…
Tacx’s strategy for the SMART trainers has been pretty straight forward in that what you are purchasing is the trainer which includes the motorbrake, stand, and a front wheel support. Additional accessories available for purchase separately would include a handlebar clip on holder contraption for a tablet, the Upgrade SMART T2990 which is really only necessary if you want to use the trainer with Tacx’s desktop software, and a Tacx steering unit for use in the Tacx VR worlds. The upgrade SMART kit includes a Tacx ANT+ powered USB antenna, ANT+ handle bar controller (from iGenius), and TTS Advanced. If all you want to do is use a SMART trainer with 3rd party FE-C compatible apps like Zwift or Trainer Road, then I think all that is required is device that is ANT+ capable or desktop PC with an ANT+ USB antenna.