This is the optional Team Associated RC8B3.1 Underdrive Differential Gear Set. This gear set for the RC8B3.1 and RC8B3.1e V3 differentials is great for low traction tracks. The underdrive gear set slows down the rear tire rotation compared to the front, making it more stable on low grip surfaces.

Features: 

• Using underdrive gears in the rear end makes the rear tires rotate slower than the front
• Beneficial when running in low traction conditions to smooth out the car's responsiveness
• Compatible with RC8B3.1 V3 differentials on the RC8B3.1 and RC8B3.1e

Includes:

• (1) Diff Pinion Gear, 12T
• (1) Diff Ring Gear, 42T