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