The Slash 4X4's fully adjustable suspension gives it an edge in any race, and with Traxxas progressive-rate tuning springs, you can hone your truck's handling to an ever greater degree of precision. Custom-wound specifically for Slash 4X4, the tuning springs are available in four rates to suit any setup. The progressive-rate design allows small-bump compliance without compromising big-hit capability, and the white powder coated finish guarantees lasting good looks. The springs are color-coded to indicate rate, and are sold in pairs in front and rear lengths. Custom wound for Slash 4X4. Progressive-rate design allows small-bump compliance without compromising big-hit capability. Durable powder coated finish. Color-coded to easily identify spring rate.