The Gtechniq Detailing Brush is made with synthetic fibres to ensure the perfect mix of strength and durability. They contain no metal parts, so there is no chance of scratching or marking the bike frame. These brushes are particularly well suited to aim in the cleaning of cassettes and derailleur.Optimal firmness for cassette and derailleur cleaningDoes not contain any metal partsHighly durableSimple Steps To Help You Get The Best ResultsApply product to the surface and then agitate the surface with a detailing brushClean brushes with clean water and using the handle holes, hang and allow to dry.