both come with a screw threaded in the throttle housing that allows you to govern the throttle so your little one cannot reach full throttle. This is great as beginners tend to wind the throttle on fully and hold it on the limiter. The screw stops them from achieving full throttle so the bike will not take off so aggressively or build up to full speed. As they progress and learn better throttle control you can slowly wind it out and give them more and more throttle each time they ride the bike until they are used to
