This is the Hot Racing Traxxas TRX-4M Brass Differential Cover. This optional brass differential cover was constructed from high quality brass and is a great way to add 20g of unsprung weight to lower the center of gravity and increase the durability of the front and rear TRX-4M axles
 
Features:
Perfect fit for the TRX-4M
High quality brass
20g of unsprung weight
Includes:
(1) 20g Brass Differential Cover