This is the Stock Replacement Spur Gear for the HPI Savage .21 Truck.
This is the main gear that meshes with the clutchbell.

FEATURES: Black plastic construction

INCLUDES: One 52 tooth gear
One slipper pad

REQUIRES: Nothing. This is a direct replacement gear.

SPECS: Outer diameter: 54mm (2.1")
Thickness: 7mm (0.28")
Pitch: 1M