Mugen MTC2 progressive shock springs
New from Mugen for the MTC2 are a pair of new progressive shock springs. Compared to the standard springs, the steering and stability will be improved, especially on tracks with bumpy surface conditions. By using A2540 (7.0P) for the front and A2539 (6.5P) for the rear, the car rolls more smoothly and it increases the accuracy by turning into corner entrance. A2540 (7.0P) can be used for both front and rear, as well as for small tracks and also for stock motors.
Source: Mugen [mugen.eu]