Referring to FIGS 2 and 3, {TAIL ~ the lumens} 18,20 share a common wall 26, which extends entirely from the base 14 to the distal end 28 of {HEAD ~ the dual duckbill valve} 
Referring to FIGS 2 and 3 , { TAIL ~ the lumens } 18,20 share a common wall 26 , which extends entirely from the base 14 to the distal end 28 of { HEAD ~ the dual duckbill valve }
OTH OTH OTH OTH OTH OTH OTH 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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD