a slider held within the housing and in {HEAD ~ sliding contact} with {TAIL ~ the second portion} of the arm inside of the housing 
a slider held within the housing and in { HEAD ~ sliding contact } with { TAIL ~ the second portion } of the arm inside of the housing
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH