Preferred age: 3 This 140-piece set of Track Ball Magnetic Building Blocks provides an expansive and imaginative play experience. The magnetic blocks, measuring 7.5CM, allow children to easily construct elaborate track ball systems. With the added lighting feature, the structures come to life, creating a vibrant and engaging play environment that stimulates creativity and learning. Note: Adult supervision is recommended as this toy may contain small parts that could pose a choking hazard.