To prevent leakage of gas from within the cell the substrates have {HEAD ~ sealing areas} 24 at {TAIL ~ opposite edges} to cooperate with the sealing surfaces on the plates 
at
To prevent leakage of gas from within the cell the substrates have { HEAD ~ sealing areas } 24 at { TAIL ~ opposite edges } to cooperate with the sealing surfaces on the plates
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH