Traxxas 5136X Differential Oil Kit (10,000, 30,000, 50,000) Differential oil kit features 1 each: 10K, 30K, 50K weights Traxxas differential oils allow you to change the locking action of your sealed differentials Thicker oils provide more differential locking action Altering the limited slip capability can enhance turning performance for faster exit speeds Use Traxxas stock and hop-up replacement parts to get the most out of your Traxxas RTR vehicles