Marketing Color: Natural JT Sprockets are made from the latest generation of computer design and control metal cutting equipment for maximum durability. JT rear sprockets are made from the finest C45 high carbon steel. All sprockets are heat-treated and hand-finished to meet or exceed the highest possible quality standards. Induction hardened with black zinc finish available on certain sprockets. This item fits the following vehicle applications: 1978-1979 fits YAM RD400 1977-1981 fits YAM XS400 1978-1979 fits YAM XS400-2 1976-1978 fits YAM XS500