Traxxas 8362X Blue shock springs are designed for use on the 4-Tec 2.0 chassis. 3.7 rate, sold as a pair. Use Traxxas stock and hop-up replacement parts to get the most out of your Traxxas RTR vehicles. This product is made from high quality materials and designed for long-lasting performance. This is replacement hardware for use on Traxxas vehicles; consult your users manual for exact parts listings.