Original Name / Part No.: AX31384Part location: Front/rear gearbox areaProduct major functions & usage: Stabilize and provide protection for the differential gears for smooth operation. Brass material can also be used as external weight for the vehicle. Accessories: Gearbox Cover 1pcStainless Steel Cap Head Screw 2.5x16 4pcsMajor advantages of upgrading to this part/product :1. Made with a good quality brass for great durability and protection. Weighing at 35 grams, this part has good weighing effect. 2. Precisely made to minimie the gap on bearing, making the differential operation more stable.3. An opening for oil-filling was added on the design for convenience.