This is an optional part for RD2.0/SD2.0 that combines an aluminum rear H-arm and a brass weight to systematically increase rear traction. By mounting a weight (sold separately) with a rigid aluminum H-arm, it is possible to increase the unsprung weight that is directly applied to the rear tire, effectively increasing the traction of the tire. Unlike increasing the weight of the chassis, the load is applied regardless of the pitching motion, so the slide fits well and the stability can be maintained even when entering a corner. By adding an additional 5g or 10g weight to the base 20g weight, you can control the load applied.
