In a vehicle's suspension the upper mounts connect the strut or shock assembly to the body. Most factory mounts are constructed from soft rubber or plastic & are designed with ride comfort as priority. Under spirited driving conditions, the factory mounts can flex & distort, hindering the performance of the shock absorber or strut. This may cause the vehicle to lose traction & steering response. The HKS Pillow Ball Upper Mounts are constructed of aluminum & steel for maximum strength & are engineered to enhance the ability of yours performance suspension.