Traxxas 8150 driveshaft extension kit is intended for trx-4 trucks using the long arm lift kit. Includes two long and two Medium drive shafts. Use Traxxas stock and hop-up replacement parts to get the most out of your Traxxas 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.