This is the Finish Line Grunge Brush. The Grunge Brush makes chain and gear cleaning a breeze! Keeping your drivetrain clean helps to increase the useful life of your drivetrain and helps to prevent premature wear of critical and expensive components. Use the horseshoe shaped brush to clean all four sides of the chain, as well as the chain rings. Use the long bristles on the other end to clean the cassette, derailleurs, and pulley wheels! Grunge Brush can be used dry in between rides, or with a cleaner for a deep cleaning. Use it with a citrus based chain degreaser or multi bike degreaser by simply spraying degreaser onto the chain or directly onto bristles. Grunge Brush scrubbing action, combined with a chain degreaser, will make it easier than ever to keep your drivetrain looking like new!