Really good hop up.
This is one of the most important hop ups for a TT-01.
I like this product more then just the single propellor shaft, because it also comes with the joint shafts, which really make a difference.
With this your car wears less and it can reach a high speed amount.
If you use a low turns motor or brushless motor, then you really need this.
Buy this if you haven't got it yet for your TT-01. Nice price and really good product!