The helical design assures a smooth, virtually noiseless brushing action due to constant brush contact with the cleaning surface. It is the only disposable type brush featuring a helical, totally enclosed aluminum solid face housing. If required, we can also supply brushes in straight face construction. Our standard bristles come in three diameters: .014, .028 and .040. A wet carryover requires a heavier bristle than a dry carryover. A heavy carryover, such as iron ore, would require the .040 bristle. A light carryover, such as cereal, would require the .014 bristle.