The two end plates 514 {HEAD ~ each} include an opening 518 into {TAIL ~ the passage} 516 
The two end plates 514 { HEAD ~ each } include an opening 518 into { TAIL ~ the passage } 516
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH