Product information This is a steel bearing. It can increase the speed of mechanical movement performance. Use it to connect parts for smoother movement. It is a necessary part for mechanical connection.Its internal steel ball with oil. Helps to lubricate and dissipate heat. It can be applied to any mechanical joint part, Of course, some of the joint size can be matched. Here it applies to remote-controlled trucks, For Traxxas XRT 1/6 Front Steering blocks & C-hub rear Carrier.