{TAIL ~ a locking mechanism}, provided on each of the sockets, for locking the plug body engaged in the associated socket and preventing the plug body from being disengaged in {HEAD ~ the axial direction} thereof, 
{ TAIL ~ a locking mechanism } , provided on each of the sockets , for locking the plug body engaged in the associated socket and preventing the plug body from being disengaged in { HEAD ~ the axial direction } thereof ,
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH