This is a set of replacement Green 3.5 rate shock springs for the Traxxas Revo monster truck. These are the rear standard springs that come with the truck and used with the 90mm Progressive 1 suspension. 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.