The knob 82 and dial 84 can be {HEAD ~ part} of {TAIL ~ an electronic device} 
The knob 82 and dial 84 can be { HEAD ~ part } of { TAIL ~ an electronic device }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL