This is a Hot Racing lightweight steel center one-way differential for the Traxxas Slash 4x4 and Stampede 4x4.
1x Center One-Way Differential with Pre-Installed Bearing
1x Lightweight Steel Shaft
3x M3x5mm Screw
IF you do not have a 4x4 Slash or 4x4 Stampede with the center differential you will need a Hot Racing or Traxxas Center Differential Gear.
One-way mode for racing tight tracks where maximum off-power steering is needed.