Robotics is a vast, thrilling, and sometimes overwhelming interdisciplinary field involving physics, engineering, and computer science. This kit gives kids a simple, fun, and customizable introduction to robotics that lets them build eight motorized machines controlled by programs and an ultrasound sensor. Kids code the programs using an easy, visual programming app on a tablet or smartphone, which connects to the robot models via a wireless Bluetooth connection. The ultrasonic sensor works on the same principle as sonar. It sends out sound waves, which bounce off objects. The sensor interprets the echoes returning to it, and from this detects objects in the path of the sensor. Using the app interface, you can program the robots you build to behave based on the feedback coming from the ultrasound sensor.