This is a set of eight RPM Delrin Shock Pivot Balls and are intended for use with the Associated RC10 and RC10GT truck using RPM suspension arms. These RPM GT Delrin® Shock Pivot Balls are a must have upgrade when using RPM GT Front A-arms. RPM GT Front A-arms have captured style lower shock mounts and RPM pivot balls align the bottom of the shock correctly to maintain proper stock suspension geometry.