{HEAD ~ The invention} features {TAIL ~ a rubber thread} that has, in cross section, two or more rubber portions 
{ HEAD ~ The invention } features { TAIL ~ a rubber thread } that has , in cross section , two or more rubber portions
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH