The pressing device presses the retractable unit toward {HEAD ~ the open position} in which {TAIL ~ the unit} is extended 
The pressing device presses the retractable unit toward { HEAD ~ the open position } in which { TAIL ~ the unit } is extended
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH