This is the Hot Racing 11, 12 Tooth Steel drive sprocket set.

FEATURES:
6061 CNC Aluminum drive Gear with 11 and 12 tooth hardened steel sprocket set.

INCLUDES:
One 6061 Aluminum drive gear One Stock (11 tooth) Steel Sprocket One Speed tune (12 tooth) Steel Sprocket

SPECIFICATIONS:
Thickness: 0.44" (11.28mm) Gear diameter: 0.7" (20mm)