Amazon.com: Dowling Magnets Alnico Magnet Science Kit. Magnets for Kids Including 2 Horseshoe Magnets, 1 Bar Magnet, Iron Filings and Iron Shapes for Fun Science Experiments. Item 731009. Ages 8+
Amazon.com: General Tools 370-2 Horseshoe Power Alnico Magnets, 12-Pound Pull : Industrial & Scientific