Robotics: Smart Machines - Tracks & Treads from Thames & Kosmos is a hands-on STEM kit that teaches children robotics and visual coding by building motorized machines that use continuous tracks. The kit includes buildable models driven by motors and an ultrasound sensor and is programmed with a Bluetooth-compatible visual app for iOS and Android. Models include a tracked driver that avoids obstacles, an attentive tracker that follows your hand, a conveyor belt, an escalator, a dozer, and a fire rescue robot, all assembled with a full-color step-by-step manual; tablet or smartphone required and not included.