Editorial Review TRB RC Front and Rear Differential Ball Bearing Set with Blue Rubber Seals for Traxxas X-MAXX.NOTE: Does NOT include the 2 bearings for Center Gear.Includes:1ea 12x18x4mm BLU-6701-2RS, Replaces Traxxas # 51202ea 15x24x5mm BLU-6802-2RS, Replaces Traxxas # 5106, 5106A4ea 17x26x5mm BLU-6803-2RS, Replaces Traxxas # 5107A7 Ball Bearings TotalChromium Steel 52100 (GCr15) ABEC 3 Races Hard Chrome GCr15 BallsRubber Seals to Help Fight Dirt