{HEAD ~ The first and the second blocks} are formed in {TAIL ~ a center area} of the tread surface between the two third main grooves 
are formed in
{ HEAD ~ The first and the second blocks } are formed in { TAIL ~ a center area } of the tread surface between the two third main grooves
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH