Each 1.6-inch cube contains an eight-megahertz processor preprogrammed to execute one function. The six-block starter kit includes a rechargeable battery brick, as well as cubes that roll on rubber wheels, display an LED at varying intensities, and detect changes in lighting. Users configure the blocks however they choose, and the arrangement determines how the finished robot acts. (Magnets hold the blocks together, allowing copper connectors to transmit data between cubes.) The kit can make about 30 different robots; attaching the battery block to wheeled and light-sensitive blocks, for example, produces a robot that walks when the lights turn on.