A pin is mounted downwardly on the flatbed unit, such that the pin can be received in {HEAD ~ the slot} for connecting and disconnecting {TAIL ~ the flatbed unit} from the tractor unit 
for connecting
A pin is mounted downwardly on the flatbed unit , such that the pin can be received in { HEAD ~ the slot } for connecting and disconnecting { TAIL ~ the flatbed unit } from the tractor unit
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH