The HSP 60221 metal gear replaces the stock plastic gear in the HSP 1/10 Grampus 2WD buggy and monster truck.The gear has 34 teeth with a 48 tooth pitch.The metal gear is far more durable than its plastic counter part and as such is a must upgrade for the Grampus gearbox.The metal gear upgrade can take more punishment so the slipper clutch can be set a little stiffer getting the power from the motor to the wheels even quicker than before resulting in faster starts off the line.