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 colours, green, blue, purple and white have their north poles directed outwards. The warm colours, red, orange, yellow and pink have their south poles directed outwards Attract - Repel: Unlike poles attract, like poles repel. All bars with a cold colour can be connected to all bars with a warm colour. All other combinations repel. Balls: SmartMax balls are attracted by all bars, regardless of their colour. 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 3 Large Poles 8 Metalic connection balls.