An inner periphery of the socket is provided with a seal ring for sealing an interval between the inner periphery of the socket and an outer periphery of {HEAD ~ the plug} in an airtight manner and a hold ring for restricting movement of the seal ring in {TAIL ~ an axial direction} 
An inner periphery of the socket is provided with a seal ring for sealing an interval between the inner periphery of the socket and an outer periphery of { HEAD ~ the plug } in an airtight manner and a hold ring for restricting movement of the seal ring in { TAIL ~ an axial direction }
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 OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL