hey guys.. whats the upper pillow ball mounts on a suspension?

Im asking because im deciding whether to get the Tein SS or the Tein Flex coilovers.. the Tein Flex comes with upgraded upper pillow ball mounts while the Tein SS do not.. is it really necessary to get those upgraded upper pillow ball mounts?

 

those mounts aren't necessary. They make for a firmer ride becasue they replace the stock mounts.