OEM Precision Replacement: Directly replaces ARAC3999 and ARAC4027 differential components. Maintains factory specifications for perfect fitment with Arrma 3S BLX drivetrains. Multi Model Compatibility: Designed for Arrma 1/10 Big Rock 4x4 V3 3S BLX, Granite 3S BLX, Senton 3S BLX, Vorteks 3S BLX, and Typhon 3S BLX. Ensures universal performance across the 3S series. High Strength Steel Construction: Forged from hardened alloy steel with CNC-machined teeth. Resists wear under high-torque loads for extended service life. Optimized Gear Geometry: Redesigned 28mm planetary gear set improves power distribution efficiency. Minimizes heat buildup during aggressive bashing sessions. Complete Upgrade Kit: Includes 2x precision matched drive outdrive gears (28 mm/1.09 inch x 14 mm/0.56 inch). Ready to install with pre greased bearings for immediate drivetrain reinforcement. for Arrma 1/10 series