The components which define the three points of {TAIL ~ engagement} with the test member are mounted on {HEAD ~ this frame} 
The components which define the three points of { TAIL ~ engagement } with the test member are mounted on { HEAD ~ this frame }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD