[6mm 9 Teeth]
Specifications:
9T Gear Outer Diameter: 21mm; Step Diameter: 12mm
10T Gear Outer Diameter: 23mm; Step Diameter: 16mm
11T Gear Outer Diameter: 25mm Step Diameter: 16mm
Outer diameter of 12T gear: 26.5mm Step Diameter: 16mm
13T Gear Outer Diameter: 29mm Step Diameter: 18mm
12 Teeth In Picture