5Pack ShareGoo Steel 48P 3.175mm Pinion Gear Sets 33T 34T 35T 36T 37T fit 3.175mm (1/8-Inch) Shaft Compatible with Arrma HPI Kyosho Losi Axial Traxxas Tamiya Associated 1/10 RC Car Monster Truck Buggy

Using these to try to get different speeds out of my 4-tec. They are sturdy and seem well built. Like the fact that they are labeled so I don't need to keep track of them.

This is one of the most significant upgrades you can make to your car without changing the motor. I changed from the 27T to the 37T and the car is significantly faster. Highly recommended upgrade

Nice variety of durable gears. Perfect for 1/10 scale rc cars.

Purchased this set as it contained the range of gear options I was looking for. I did not have particularly high hopes based on the price, but I thought I would give it a try. Well packaged and included a hex key. They appear to run true and are labeled. However, only two of the pinions is actually tapped properly. The set screw in 3 is quite loose - to the point where I am uncertain in threadlock will be enough to stop it from backing out. That is enough for me to say you should probably pass on these.