The littleBits kit is like Lego for basic circuits. Each “bit” is a small circuit board that enables a single electronics component or electronic function, like a potentiometer, light sensor, LED, or motor. The bits snap together magnetically with edge connectors that are color-coded to indicate their general role within a circuit; for example magenta means input, green means output, and blue means power. The magnets are oriented so that you cannot connect the bits the wrong way, and three spring-loaded contacts in each connector carry voltage, signal, and ground from bit to bit. This clever design makes experimenting with series circuits easy and “wireless.”