Worm Wheel Bore Diameter 12 mm Bore Diameter Tolerance +/- 0.2 mm Bore Type Plain Face Width 20 mm Gear Shape H4 Hub Diameter 40 mm Hub Projection 14 mm Material Aluminum Bronze Metric Module Pitch 2.5 Number of Starts 1 Number of Teeth 30 Outside Diameter 82.5 mm Overall Length 34 mm