...Sold to Ron. RSR Rear Suspension Coil-Overs Steel Crossmember.

This is the RSR rear crossmember that allows the use of RSR coil-over shocks and springs. The street 911 chassis uses a much smaller receiver cup for the street suspension. You cannot use the Bilstein RSR rear coil-over shocks and racing springs unless you have this component incorporated in your chassis. This part was cut out from a race car.