Build the ultimate ball track with this new magnetic construction set that contains an amazing 71 pieces! With endless options you can make all kinds of crazy machines and let the balls roll. Mega Ball Run contains special parts including tubes and X-shaped bars with 4 magnetic ends. It enables young children to explore magnetism safely, with strong, oversized pieces that are specifically designed for handling by young kids. Our magnets are incredibly strong, able to carry up to 60 times their own weight! The magnetic bars feature unqiue color codes: "Cold"-colored bars (blue, green, purple) attract "warm" colored bars (red, orange, yellow). Warm-colored bars repel other warm-colored bars, cold-colored bars repel other cold-colored bars.