The Mobile Spy Ear is a listening device in a pull-back vehicle! Pull it back, let it go, and send it in to spy. Listen in to other rooms, through walls, up to 50 feet. 2 ways to play: roll it in, or place it in a room. Includes mobile listening bug, receiver with ear bud. Parts snap together to store or clip onto your belt. 2 9 Volt Batteries Required.