Use this set of Traxxas pre-load spacers to adjust the ride of your Traxxas Ultra Shocks. Adding these to your Ultra Shocks can raise the ride height of your vehicle and pre-load your springs. It includes two 1mm spacers, two 2mm spacers, two 4mm spacers, and two 8mm spacers. 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 user's manual for exact parts listings.