That is a fluorescent yellowish version of the Mini 4WD front under guard, which functions as a braking system and helps your car or truck stay on track after jump landings. Its 3-piece setup enables both normal and wide roller settings. Two sets of under guards with different thicknesses are included for use with large and small diameter wheels.
• Front Under Guard x 2 sets
• Molded in Fluorescent Yellow low-friction PP synthetic.
• appropriate for MA, MS, FM-A, AR, VS, Super XX, and Super-II framework automobiles.