Both the seating rim and the seating recess can be of a polygonal shape, with the seating rim fitting {HEAD ~ the shape} of {TAIL ~ the seating recess} of the sample changer 
of
Both the seating rim and the seating recess can be of a polygonal shape , with the seating rim fitting { HEAD ~ the shape } of { TAIL ~ the seating recess } of the sample changer
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 REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH