{HEAD ~ The belt portion} 10 is provided with a series of cogs 12 on {TAIL ~ the rear side} along the longitudinal direction 
{ HEAD ~ The belt portion } 10 is provided with a series of cogs 12 on { TAIL ~ the rear side } along the longitudinal direction
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH