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