Dorhea 12PCS SG90 Micro Servo Motor, Mini Servo SG90 9g Servo Kit for RC Helicopter Airplane Car Boat Robot Arm/Hand/Walking/Servo Door Lock Control with Dupont Cable Compatible with Ardu ino

These are typical, no better or worse than others. All 12 that were shipped work perfectly.I do like that the plastic gears will tolerate a bit of "grinding" if the load is too heavy, but otherwise these are typical but very good for the price.

These are not great quality servos. From my experience they have about a 5-10% DOA rate, and they also do not last as long as higher quality servos, even if they are not DOA. However, they are cheap as heck. If you need a bunch of cheap servos to do the job of cheap servos, this is a fine deal. $1.58/servo is throw-away money, but these are throw-away servos, you get what you pay for. If you want high-quality, precision servos for critical applications or use in twitchy or valuable flying models, look elsewhere.

Have tried to use as a replacement for aileron and find that I have to replace both because it operates the same direction as the old unit, on the other side.

I used the servos to control model railroad turnouts and so far they are working well. They came nicely packaged in and secure box. I tested all of them and they all worked and are working well on my model railroad. Good product, good price and they arrived on time.

I installed 4 of these over the course of a few days, and am returning them. I gave them a chance hoping the first 1 or 2 were a fluke, but not the case. I usually use tower pro servos and they generally last 1-2 months for what I use them for, every once in awhile I will get a dud that dies within a week.I decided to save a couple dollars and give these a try. Out of 4 installed servos 2 were humming very loudly from the moment they received power, 1 was doa, and 1 was quiet. One of them lasted an astonishing 2 days while the other 2 I used lasted half and 3/4 of a day each, then of course the DOA one which just wasted my time.These servo motors are generally cheap and not expected to have a mega long life, but going from 1-2 months to a day or 2 lifespan is pretty pathetic. The other odd thing is when 2 of them went out they smelled pretty strong of burning motor which I have yet to experience with the tower pro servos. With how hot they were and how strongly they smelled it is definitely a bit worrisome.