Fusible closure melts in event of fire, releasing dangerous pressure build up inside the c ontainer. Pre-assembled unit crimps onto opening in cover, includes a 2" plug with a 3/4" reducer opening and a metal crimp ring for secure installation. A molded, pre-scored diaphragm forms a hermetic, tamper-evident seal. Diaphragm has convenient pull ring for
easy removal. Crimping Tool easily and accurately installs closure.