Easy_company Diameter Ceramic Disc Magnets, Science Project, Crafts ~Bulk Lot 40Pcs.(Diameter 20mm (0.787 Inch)) Great for all home, office, craft, hobby, science projects and product manufacturing applications. Not a toy, for craft, science or production use only. 20 mm.(0.787 inches Diameter, Flat Disc Magnets with Beveled Edges)