{HEAD ~ The filler composition} may contain a thickening/thixotropic agent, such as {TAIL ~ silanized pyrogenic silica} 
{ HEAD ~ The filler composition } may contain a thickening / thixotropic agent , such as { TAIL ~ silanized pyrogenic silica }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL