This product is installed in the rear wheel flywheel, used to protect steel wire. It is made of transparent plastic and has the following dimensions: rotary external diameter 138 mm, internal diameter 37 mm, rotary outer diameter 164 mm, inner diameter 37 mm. The card V brake diameter is 135, suitable for road vehicles, folding cars, and mountain bikes V brake drum. The external diameter of the card disc brake is 164, the internal diameter is 68mm, suitable for each model and the head disc brake drum. The package includes 3 PCS.