For EU models; Stage 1. The Thunderslide for Harley-Davidson has set a benchmark in jet kit design. It incorporates a custom made throttle slide of which the unique profile allows precise control over the slide''s range of movement. It creates a stronger signal; improving fuel atomizing which is essential for a good fuel burn. This provides more power; increased throttle response and improved fuel economy. MCS vehicle fitment: 98-03 XL1200S (NU)