Yokomo RP Ultra Progressive Shock Springs are the same springs used on the world championship BD 8 machine. The "Progressive" type springs get stiffer as they compress, and this was achieved by changing the winding pitch within the spring. All RP springs are black, with the spring rate laser engraved on the end face of the spring. Plastic case included.
These are the 2.6-2.8 springs which are the softest in the progressive series.
This product was added to our catalog on July 25, 2017