Worm Wheel Bore Diameter 6 mm Bore Diameter Tolerance +/- 0.1 mm Bore Type Plain Face Width 11 mm Gear Shape H1 Hub Diameter 20 mm Hub Projection 9 mm Material Bronze Metric Module Pitch 1.25 Number of Starts 2 Number of Teeth 20 Outside Diameter 28.8 mm Overall Length 20 mm