S&S CYCLE Replacement Air Filter Back Plate Harley Davidson FLHX / FLHXU / FLTRX 1923-1977 23-25

S&S Cycle is a renowned American motorcycle engine and performance parts manufacturer, founded in 1958 by George J. Smith and Stanley Stankos in Blue Island, Illinois, before relocating to Viola, Wisconsin in 1969 . Initially offering high-performance pushrods for Harley-Davidson V‑Twin engines, the brand has since expanded into complete engines, exhausts, and premium bolt-in components