The other of the pair of apertures to cooperate with {TAIL ~ the output end} of {HEAD ~ the rotary shaft} to form a second connection 
The other of the pair of apertures to cooperate with { TAIL ~ the output end } of { HEAD ~ the rotary shaft } to form a second connection
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH