There are three main filament choices for most wafer brushes: polypropylene, steel wire ,Polypropylene and steel wire mixed
1.Polypropylene offers a soft filament that won't cut into the harder road surfaces. Will not easily damage the ground2. steel wire , Polypropylene and steel wire mixed filament:These highly abrasive brushes are well suited for cleaning road and snow,or heavier industrial applications,like metal finishing and
cleaning.