{TAIL ~ The rolling elements} are arranged at the vertices of a triangle with respect to {HEAD ~ a plane} that is parallel to the guides 
{ TAIL ~ The rolling elements } are arranged at the vertices of a triangle with respect to { HEAD ~ a plane } that is parallel to the guides
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH