These are front suspension arms for the electric Rustler and Stampede-based models, both 2WD and 4WD. They are formed from a durable nylon composite and sold in pairs. 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.