Pivot Cups are small pieces of soft plastic which are used by almost every professional fingerboarder in the world. They are placed in the hole in the baseplate as seen in the picture before putting on your hangar and it keeps that area tighter in order to get more solid trucks. Pivot cups and a set of good bushings are the key to tight, locked trucks to give you loads of pop on all your tricks. Comes in sets of 2 for $1/set. Colors are random.