The cover can be formed of a polymer blend including a polyurethane composition and {HEAD ~ the core} can include {TAIL ~ a polybutadiene composition} 
include
The cover can be formed of a polymer blend including a polyurethane composition and { HEAD ~ the core } can include { TAIL ~ a polybutadiene composition }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL