Designed for a sharper, leaner spark with tapered nickel/chrome alloy tip and copper center electrodeMade in the U.S.A. Harley-Davidson -- Duo Glide FL -- (1962, 1964, 1960, 1958, 1961, 1959, 1963); Harley-Davidson -- Hydra Glide FL -- (1954, 1957, 1951,...