a printing element having an impacting surface at its front end and {HEAD ~ a driven surface} at {TAIL ~ its rear end} 
at
a printing element having an impacting surface at its front end and { HEAD ~ a driven surface } at { TAIL ~ its rear end }
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