{HEAD ~ The higher protruded walls} 4011, 4021, 4031 thereof are circumscribed by {TAIL ~ a lower stop wall} 404 extending upwards at the outside thereof to form a channel groove 405 therein for the sealing ring 43 of the same shape to be adapted in sleeve engagement therein 
are circumscribed by
{ HEAD ~ The higher protruded walls } 4011 , 4021 , 4031 thereof are circumscribed by { TAIL ~ a lower stop wall } 404 extending upwards at the outside thereof to form a channel groove 405 therein for the sealing ring 43 of the same shape to be adapted in sleeve engagement therein
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL REL TAIL 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 OTH OTH OTH