Traxxas 3768 Upper and Lower Spring Retainers and Piston Head Set (pair) Replaces broken or missing spring retainers Includes upper and lower spring retainers Tunes Ultra Shock compression and rebound with optional pistons Fits all Traxxas Ultra Shocks Use Traxxas stock and hop-up replacement parts to get the most out of you Traxxas RTR vehicles This product is made from high quality materials and designed for lasting performance This is for use on RC vehicles, consult your user's manual for exact parts listings