wherein the first cylindrical portion has an outer peripheral surface from which a flange protrudes radially outward, {HEAD ~ the flange} being in contact with the protruding end of {TAIL ~ the cylindrical portion} to define a gap between the lid portion and the semipermeable membrane in the sliding direction 
wherein the first cylindrical portion has an outer peripheral surface from which a flange protrudes radially outward , { HEAD ~ the flange } being in contact with the protruding end of { TAIL ~ the cylindrical portion } to define a gap between the lid portion and the semipermeable membrane in the sliding direction
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 TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH