"The Moon Walker II combines the technology of two sensors. It begins to walk when it detects a change in light intensity or sound commands, and will continue until instructed by an internal timer to stop. It presents an opportunity to learn about some of the mechanics operation and history of robots. Light and sound sensors may be adjusted to different sensitivity levels.Specifications: Movement: 2 legs on each side by crank shaft. Control: Sound sensor including condensor microphone/transistor; Light sensor/photo transistor. Power Source: ""AA"" x 1 (not included). Size: H130 x Diameter 100mm. Power Consumption: Approx. 210mA. "