Designed with motorsports use in mind to replace the tear-prone soft rubber factory transmission mounts, a common cause of knocking, mis-shifting and over-revving. Fits RWD vehicles only. Made using CNC  machined Aluminium Caps with captive securing bolts and a Black 95A Durometer  polyurethane body, they increase stiffness over OE by 375% for complete control  over powertrain movement.They are also the perfect accompaniment to our  PFF5-4650 Tuneable Engine Mount  on E36/E46/E9*  models.