Note:Because the battrey does not allowed send by normal post,we will send without the batteries. Detail Description: The earthquake detector is designed to provide instant warning of seismic activity by detecting the "P" wave (compression wave) of an earthquake, which travels faster than the more destructive "S" wave (shear wave). The earthquake detector saves valuable seconds by removing the guesswork in earthquake detection. It is capable of detecting large earthquakes that occur hundreds of miles away and can detect moderate to minor earthquakes for many miles around your local area. One very important advantage of The earthquake detector is that it can wake you up and alert you the moment the quake starts so that you can immediately take cover or tend to other family members. The human mind relies upon the sensations from the inner ear combined with the sense of sight to determine the sensation of motion the body is undergoing at the time that an earthquake starts. Disorientation, known as vertigo, can cause people to become confused and instinctively freeze for many seconds during the onset of an earthquake. Sound also plays a part in earthquake detection and by itself can be misleading. The sound of a slamming garage door or the low rumble of a large truck has startled many people into falsely thinking that they are about to experience an earthquake. The earthquake detector can eliminate confusion, save valuable seconds and provide peace of mind.