Brand: Hot Racing
Part Number: SXMX9432TR
Hot Racing Steel Helical Differential Ring & Pinion Gear for Traxxas X-Max/XRT (Rear) (42T/13T) (part #SXMX9432TR), made for the Traxxas XRT. Pinion size is the easiest way to tune top speed against acceleration and keep motor temperatures in check; hardened steel lasts far longer than stock aluminum.