The nylon bristle of our chimney brush is helical(not straight, for higher cleaning efficiency and longer lifespan) and flexible, so you not need to trim the bristle short or get the bristle straight. With the driving force and centrifugal force from the drill chuck, the chimney brush can be used to high efficiently clean the chimneys(note, without soft lining) of inner diameter from 100mm~700mm(i.e. 4~28 inches )
By vevor