Traxxas 8156 long GTS shock springs are intended for TRX-4 trucks using the Long Arm Lift Kit. (0.54 rate, sold as a pair) 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.