This Yamaha CDI box is a new old stock (NOS) item for the RZ350 model manufactured between 1984 and 1985. It is compatible with part numbers 52Y-85540-50-00 and 29K-85540-50-00, as well as superseded part number 52Y-85540-50-00. This vintage part is perfect for anyone in need of a replacement CDI box for their Yamaha motorcycle.