Don't let the low price make you think these are "cheap" servos. These ones are the most cost effective servos for Trex 450 and it's clones. They are low cost, as you can see. They are very fast for analog servos. And they are also all metal gears and strong enough for the task. Finally, these are very relable devices. I've been flying more than a year with my first set of three MG90S' with no problem at all. My heli has taken some few crashes (none of them related to servo fealures) and they still work with no problem. Just one thing: TowerPro MG90S servos are very sensitive to electronic noise caused mostly by some digital servos. This doesn't mean you cam't mix them. Just make a ferrite coil with an iron ring and the digital servo wire, and you'll have a powerful, relaible and unexpensive cyclic servo crew.

The first sprocket is unfortunately plastic. There is no ball bearing. However, it's working ok.