These are the metal knobs used for customization. They are for 6mm shafts and the part that touches the shaft is resin, so I think they are a type that is less likely to produce noise. ※The image is a sample. The appearance may change depending on the lot. There may be scratches, rust, dullness, dirt, chips, etc. that occurred during transportation and storage. Please understand this and purchase with no returns or claims. Please inquire for multiple quantities.