This set provides four Circuit Blox 72 kits (CB-0163), all packed into a sturdy storage case for sharing in the classroom. Contains 140 parts. Requires 12 " AA" batteries. Each kit provides hours of fun and educational play. The colorful building blocks contain electronic components such as a battery module, switches, LEDs, generator and nerve tester. Each kit builds 72 different 3D circuits that teach STEM and light a heart or star, use a hand crank to generate power, or tests your nerves through a maze.