This is the 64P 86T Precision Diff Gear from Kimbrough.

FEATURES: Nylon construction Black in color

INCLUDES: One Precision Diff Gear

REQUIRES: Installation on vehicle

SPECS: Outer Diameter: 34.5mm (1.36") Inner Diameter: 9.5mm (0.37") Width: 5mm (0.20") Pitch: 64 Tooth: 86