Goes together with the interior flange and inner locking band (with centering extension). The outer locking band is on the outside for more help, which makes it a more powerful method. ROCKWOOL fire stopping items act to sluggish and stop the unfold of the fire in a setting up. Discover https://trevorsiwjx.bloguerosa.com/35932019/getting-my-grease-tight-extract-ductwork-to-work