Ultra-sensitive Geophone circuit 'listens' to vibrations in the ground. Ever received reports of Footsteps? You can place this kit inside or outside and watch the changing LEDs to see if there is someone or something coming. The closer it gets, the higher the LED reading. You can also detect bangs and creaks in the floors or walls. Have you ever had reports of the bed shaking or vibrating, you can place this device on the head board or bed frame and fix a camera on it through out the investigation, the LEDs with light up the moment Vibration or movement occurs.