麻麻 la .. just a Castle sensorless system, (well, water proof) I am going to upgrade mine to Hobbywing Xerun ...
The stock servo is also near useless in such a big heavy car, ~ just 135oz .. Kit is much much better deal, if I have so much free time, surely go with the Pro kit!
~ Slightly bigger than 1/7, and same size as 1/6 ...