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