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