{HEAD ~ Each} of {TAIL ~ the lower slide bars} employ a roller bearing member while the upper slide bar utilizes a low friction bushing 
of
{ HEAD ~ Each } of { TAIL ~ the lower slide bars } employ a roller bearing member while the upper slide bar utilizes a low friction bushing
HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH