VEVOR Chimney Sweep Kit 33FT Length, Chimney Brush Kit with 10 Nylon Flexible Rods and 2 Brush Head, Rotary Chimney Cleaning Kit Driven by Drill, Chimney Brush Rod Kit for Cleaning Fireplace

The nylon bristle of our chimney brush is helical and flexible, so you don't need to trim the bristle short or wait the bristle gets straight if your chimney diameter is small than 45cm (17.7inch ). With the driving force and centrifugal force from the drill chuck, our 45cm (17.7inch ) diameter chimney brush can be directly used to high efficiently clean the chimneys(note, without soft lining) of inner diameter from 100mm~700mm (i.e. 4~28 inches).

No, you don't have to trim the bristles down according to the diameter of my flue.

Our chimney brush is designed for sweeping chimney/duct ( either bricks, or stone or steel material, and without soft lining; ) . Is your metal chimeny with any soft inner lining? If not, then you can use our chimney brush for sweeping. If yes, to protect the lining, you need find softer brush for the cleaning.