This is the optional Sway Bar Kit for the Traxxas Slash 4x4.FEATURES: For front and rear application to reduce chassis roll in turns and add stabilityINCLUDES: Two thick and two thin swaybars, two mounts, two linkage sets, mounting haardware and instructionsREQUIRES: Installing at front and rear of chassis lmm 04.12.10 ir/jxs