The JUMBO sized magnetic marbles come in at 1.33" in diameter and are not a choking hazard. Watch as they spin, attract and repel each other on a table, a fun way to learn about magnetism. All our magnetic marbles are created with safety in mind. Too large to be a choking hazard and a fun way to learn about magnetism. Large magnetic marbles teach magnetism in a safe and easy-to-handle way. Measures 1.33" in diameter. Recommended for ages 3-6 years. Includes 5 Jumbo colored magnetic balls.