6" DuraVent DuraPlus 36" Close Clearance Shield 6DP-CCS36 6" DuraPlus 36" Close Clearance Shield is used in installations where a 7" or 8" DuraVent chimney system passes through a roof opening with less than the normal 2" minimum clearance to roof trusses or rafters. Chimney pipe must be centered within Close Clearance Shield. Diameter: 6" Height: 36" Use in installations where a 7†or 8†DuraVent chimney system passes through a roof opening with less than the normal 2†minimum clearance to roof trusses or rafters Chimney pipe must be centered within Close Clearance Shield .016†430 stainless steel outer wall or .018†galvanized steel outer wall. .018†aluminized steel intermediate liner. .016†430 stainless steel inner liner. Insulated layers plus ventilated air space. Locks tightly with a precision twist-lock connection.