This Mass Damper Set superbly demonstrates its excellent stabilizing qualities on Mini 4WD machines on technical courses with a lot of banked and raised sections. 3x25mm and 3x30mm stainless steel screws included. You can install these dampers at either the front or rear of your Mini 4WD machine. It is possible to adjust the movement range of the weights by changing the hex nut position. Can be used with all Mini 4WD machines.