Cheap And Discounts 194012 Non-standard Ball Bearings ( 1 PC ) Inner Diameter 19 mm Outer Diameter 40 mm Thickness 12 mm Bearing 19*40*12 mm Wholesale. Buy Directly From Merchant RC Pro Store. Enjoy ✓Free Shipping Worldwide! ✓90 Days Buyer Protection. ✓Easy Return. ✓Money Back Guarantee.