Factory Spec, K15471558520OGR98, Green 520x98 O-Ring Drive Chain & 13/40 Sprockets 1989-2004 Yamaha Warrior 350 YFM350X All components are Factory Spec brand Chain has a tensile strength of 8200 pounds Sprockets are made of hardened steel and built to last O-ring style means it will last longer with less maintenance than conventional chains