Lateral ends of {HEAD ~ each wrapping portion} are formed into a Z shape to produce {TAIL ~ the Z lock system} 
Lateral ends of { HEAD ~ each wrapping portion } are formed into a Z shape to produce { TAIL ~ the Z lock system }
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL