Progressive 33x160mm springs Traxxas X MaxxMulti rate springs allow the optimum spring rate for each application. These multi rate springs are soft at the beginning to soak up the small bumps, but transition to the stiff part of the rate to resist bottoming on jumps and other big hits. Two (2) Black Ex Hard springs Two (2) blue Hard Springs Two (2) Red Med SpringsFeatures: Cold coiled springs are designed to use with these progressive rates spring. High quality spring steel construction Three