5 years & up. With the Magtronix Expansion Pack, you can build bigger and more complex electronic circuits. Add more magnetic circuit blocks, switches, and other elements to your starter set. Take on the challenge of building the circuit ideas featured in the activity guide. Children can learn how a circuit works along with developing cognitive and problem-solving skills through hands-on, STEM-based play. Expansion Pack will not work without the Magtronix Starter Set (not included). Requires 3 AA (not included). Included: Switch, LED, Pulser, Dial, 5 Direction Pieces, and an Activity Guide.