Directing and concentrating structures are used mainly on water coursers with unstable channel and major sediment transport or in areas with major bank erosion. The main purpose of these structures is to redirect water flow from the stressed and very often eroded bank to the centre of the channel or other parts of the channel. where the water flow may be used e. g. https://www.jmannino.com/limited-price-Orange-Carbon-Fiber-Specialty-Material-Galaxy-Buds-Skin-p34260-must-buy/