{TAIL ~ The tractor unit} is provided with {HEAD ~ a fifth wheel coupler} which is formed with a slot 
{ TAIL ~ The tractor unit } is provided with { HEAD ~ a fifth wheel coupler } which is formed with a slot
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH