UNIOR: Product featuresmaterial: premium flex plus carbon steelsurface finish: blacken to standard DIN 50938The wrench is the basic working tool for cyclists extended tours.How to use the tool:To change broken spokes on the right side of the rear wheel, the cassette has to be removed first.Firstly remove the rear wheel, than fit the tool onto the freewheel nut.Replace the rear wheel, so that the square edge of the tool presses to the frame or derailleur hanger. After that, push the pedals in the forward direction and loosen the freewheel nut. Remove the cassette and replace the broken spoke. In order to prevent the possibility that the paint on the bicycle frame is damaged, a protective plastic plate should be inserted between the key and the frame.