Keep the Q-BA-MAZE fun rolling with this 20-marble pack. Extra marbles are a must for Q-BA-MAZE—one of MindWare’s top-selling engineering toys for kids! Marble runs are proven to enhance kids’ problem solving skills, making them one of the best STEM toys available for kids who love action.• Strengthens STEM thinking and builds key logic skills• Use the steel marbles to test Q-BA-MAZE configurations • 20 premium steel marbles in a ripstop nylon drawstring bag