Goes together with the internal flange and internal locking band (with centering extension). The outer locking band is on the outside for more assist, which makes it a more powerful method. A passive fire defense solution for air distribution techniques, smoke Management and kitchen grease ducts For the duration of https://greasetightextractductwor45566.aboutyoublog.com/43524533/grease-tight-extract-ductwork-secrets