{TAIL ~ The buffer element} is disposed on {HEAD ~ the lateral wall}, and the lateral side faces the lateral wall 
{ TAIL ~ The buffer element } is disposed on { HEAD ~ the lateral wall } , and the lateral side faces the lateral wall
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH