The Darda 50145 is a very stable and easy to install rail. The connectors fit very well and the car is super flexible. The cars are both (one we ordered) after a very short period of use (three days not used intensively) completely useless. When pressing on the maximum state no longer errichbar, or the transmission is blocked. In my view, total scrap. Such vehicles not fit for really beautiful track. We have returned everything.