A tube connection piece is rotatably connected to the coupling sleeve and has {TAIL ~ a portion} provided with {HEAD ~ a sealing ring}, said portion extending sealingly into a socket in the connected position 
A tube connection piece is rotatably connected to the coupling sleeve and has { TAIL ~ a portion } provided with { HEAD ~ a sealing ring } , said portion extending sealingly into a socket in the connected position
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH