4/ This chimney brush is designed for sweeping chimney with max one 90 degree bend， or max two "45 degree bends" , more bends will greatly low down the cleaning efficiency and cause twist/stuck/detach!
By vevor
3/ The nylon bristle of our chimney brush is helical and flexible, so you no need 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 chimney brush can be directly used to high efficiently clean the chimneys of inner diameter from 100mm~800mm（i.e. 4~31.5 inches).
By vevor
2/ This chimney brush is designed for sweeping chimney/duct ( either bricks, clay, masonry, stone or steel material；and the chimney shapes do not matter, round, rectangular, or triangle etc.) and without soft lining （the nylon bristle have sharp edge, may scratch the soft lining. So, doule check if there is any inner soft lining in your pipe firstly.
By vevor
The brush diameter is 45cm.
And Below please find more details for your references :
1/ Use eletrical drills with rotation speed range from 350rpm to 2000rpm, 24V or above DC powered drill, or 500W and above AC powered drill.
By vevor
