This set features vibration technology for autonomous crawling and exploration. It includes 4 Nano and 3 Flash Nanos to build a customizable racetrack. Designed for sensory engagement, the bots have light-up designs and insect-like motions. The price drops from $59.99 to $20.99. Shipping is free on orders over $35 or for prime members. Otherwise, it adds $6.99.