A cover plate encloses {HEAD ~ the internal chamber} housing {TAIL ~ the inertia disc}, and the internal chamber is filled with elastomeric urethane 
housing
A cover plate encloses { HEAD ~ the internal chamber } housing { TAIL ~ the inertia disc } , and the internal chamber is filled with elastomeric urethane
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH