What Brush size and Type is right for me?Brush size: brushes should be larger than the diameter of the object being cleaned by up to 2"Brush Types:Stainless Steel Crimp Wire: Thin stainless steel wires that have been crimped. Excellent for soft to medium soot in all chimneys.Stainless Steel Flat Wire: Premium flat wire for harder deposits in masonry/tile chimneys.Perlon: Black plastic fiber for light condition sweeping in stainless steel chimneys. Heat tolerant to 122°F.PEK: High Tech Synthetic Fiber for light condition sweeping in stainless steel chimneys, ducts, or pellet stoves. Heat tolerant to 300°F.