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