These parts are identified with reference to {HEAD ~ the position} of {TAIL ~ the tool} shown in FIGS 1 and 3 
of
These parts are identified with reference to { HEAD ~ the position } of { TAIL ~ the tool } shown in FIGS 1 and 3
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH