This is a MUST if you own a tmaxx classic! Look I get it reverse is cool but the constant cogging isn't. Was a little tedious installing but well worth it. After the reverse gears was removed I weighed them and it came too 88g or 3.10 oz which keep in mind is alot of weight to remove from a driveline especially rotating mass. This makes the truck so much smoother and I honestly feel like this helped the truck accelerate faster and have maybe a small bit more top speed. Regardless if it does im just happy to no longer have cogging constantly.