Hard rubber competition-quality cone springs that require Hi-lo adjustable suspension, as they sit higher than the (road-use) originals. Contains an anti-fade property and shape which helps them going off during racing and giving hopefully a season of racing before replacement. The thick top plate has an internal metric thread rather than the nut welded in place as per the standard cone springs or copies. These have a yellow dot on the metal base for identification purposes.

These springs are manufactured by a highly technical company involved in rubber used on Formula 1 cars. If using these on 10" wheels with Hi-los, cut 3/4" off the end of the center threaded bolt of the old type Hi-lo with a circlip as it will bottom out on the cone spring face and the car will sit high, for extremely lowered cars the Hi-lo face will also need machining a few mm.

Like all rubber products, they only have a certain shelf life and being fitted equates to the same. Sold each, and it is advised to fit in axle pairs.

For a softer road-use version, see C-STR687.