Silent motorcycle chains: 1. Materials: Carbon steel, 40Mn 2. Color: Nature,yellow, blue, black, colored 3. Model: 415,420,428,520,530 4. All parts are heat treatment (quenching and tempering) and controlled in a reasonable tolerance range. 5. Tensile strength: 15-20% higher than the standard. 6.Certificate of Quality: SGS 7. Riveting: Two sides riveting or four sides riveting. 8. Pre-stretching and Running in for each motorcycle chains. 9. Good lubrication with excellent grease. 10.We are also doing OEM.