before you upgrade your mounts or arms to alu, you need this. trust me, you need this on your sakura or any other 3racing chasis. This will kill the play that the aluminum mounts have and make your arms stable. a must have. one set is all you need.
A MUST HAVE part if you are going to upgrade your suspension mounts to aluminium parts, such as the 3Racing Suspension Mount RR+30 (RR3 Degree) For 3racing Sakura Zero #SAK-23/PK or the 3Racing 2 Piece Suspension Mount FR-0 For 3racing Sakura XI #SAK-X22/PK. Without the pivot ball, you cannot use these parts at all. I'm so glad someone told me as I almost ordered suspension mounts without them!