FireUp Nylon/Poly Mix Flue Brush 6" Head for Flexi Flue KitsThe flexible flue brush kits allow you to clean those difficult to get to and tricky corners. The manufacturer makes particular mention of these kits success with 45 degree bends. The smaller brush heads have been found to be very useful in cleaning clothes dryer ducts (not the foil ones). The Flexible Flue Brush Heads are made of durable Polypropylene Nylon mix fibre. When used with the Flexi Rod they are ideal for cleaning in those tricky corners,