It is a strong motor. When my finger got into the gears driven by this motor, it got torn and bled, the motor did not stop. So it needs to be handled with some care and respect. We have the motor and the battery pack, and I wanted to build with my sons some cars, but the strength of the motor,and that it starts suddenly, just on/off, not gradually, makes some problems: frequently the sudden acceleration pulls the gears apart. Still. this is just to specification, I bought a strong motor and got it. What I believe to be a real design flaw is that it does not connect well with Lego pieces;you cannot connect it directly with Lego bricks. The only way to attach it is through the holes for additional axles.One advice for other car builders: the chain is really useful, it allows you to drive both wheels synchronously, so the acceleration comes on al wheels, and does not pull the car apart.Works great bought for my son to use with his lego technic sets and it had enough power to move his winch on his crane and actually pull stuff with it!Fun toy I gave as a gift for a birthday present. It has been fun to see all of the creations the kid has come up with. I would have given 5 starts except you have to read the description to realize that you need the battery pack plus batteries to go with the toy or it won’t work.Super great choice ,Good for kids!This motor is definitely worth the buy, you will need this for any moving Lego structural besides propellers. Using Lego gears, you can soup this motor to the point your Legos start bend'in, yup, worth it.Well constructed with nice life. Priced fairlyGood productBmw model carVery fast delivery and good value for money, the item is of very good quality. A great buy, would recommend.For Lego modelNew as decribed and in origonal lego packagingTowards little Lego project for grand sonfast forward