This is a set of four optional RPM Lower Spring Cups, and are intended for use with Team Associated 1/10 scale off road shocks. RPM designed these spring cups to help alleviate the frustrations sometimes associated with shock maintenance. Your shock springs rest in these cups at the base of the shock. Sometimes, during disassembly, stock cups get clogged with debris and become difficult to remove and clean. These cups are easy to remove, clean, and reinstall and have a better shelf for the springs to rest on.