A fire transmission prevention system for use in a drainage system to prevent {HEAD ~ the transmission} of smoke and fire through {TAIL ~ the drainage system} 
through
A fire transmission prevention system for use in a drainage system to prevent { HEAD ~ the transmission } of smoke and fire through { TAIL ~ the drainage system }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL