So far: 1. Duora dual optimum system. You cannot feel it by only dry swinging but I can feel the difference between the two sides when hitting the shuttlecocks. Maybe for some people it might takes a while to start believing it, but once you notice the technology system, it is really fun. 2. Voltric tri voltage system. Still the best technology in power department in my opinion, better than rotational generator system and Namd. 3. Compact frame + Extra slim shaft. Really improve the feel of the hit.
