SMARTMAX allows kids to explore the fascinating world of magnetism in a safe way. North - South: Magnets have a magnetic north and south pole. The cold colors, green, blue, purple and white have their north poles directed outwards. The warm colors, red, orange, yellow and pink have their south poles directed outwards. Attract - Repel: Unlike poles attract, like poles repel. All bars with a cold color can be connected to all bars with a warm color. All other combinations repel. Balls: SmartMax balls are attracted by all bars, regardless of their color. More than 20 bars can be connected to one ball. Different Strengths: The magnets of the long bars are stronger than those of the short bars. Long bars can lift more weight or make stronger connections. Set Contains: 12 Medium Poles 6 Large Poles 4 Curved Poles 8 Metallic connection balls. Suitable for ages 1 & up.