Since {HEAD ~ the constitution} of {TAIL ~ the buckle} and the length adjustment are obvious, their further explanation is not made here 
of
Since { HEAD ~ the constitution } of { TAIL ~ the buckle } and the length adjustment are obvious , their further explanation is not made here
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH