I bought the King Song 14C 840 800 two months ago. Jason got it to me quickly as he had one already in stock. This EUC is the nicest I’ve ever ridden – smooth, quiet, and powerful! It blows away every other one I’ve ridden (Ninebot One, IPS, AirWheel). The features on the King Song (Bluetooth, integrated lights, etc.) are great. It was a little tricky figuring out how to use them from the sketchy instructions. It was also hard entering the unlock code that activates the advanced rider specs (30 kph). Jason was very responsive helping to get these issues resolved quickly. Thanks Jason!