This is the optional gold 3.8 rate shock springs for the Traxxas Revo monster truck. Traxxas offers a wide variety of spring rates for the GTR shocks to precisely compensate for lighter or heavier truck configurations and different rocker installations. The springs use high-quality spring steel with durable powder-coated finishes. Spring rate is indicated by colored dots on the end of the spring. These are the springs that Steve Slayden recommends for racing the Traxxas Revo for most track conditions. These are slightly heavier than the stock springs.