The Sanji JSS900 impact sensor uses Patented Technology to eliminate false alarms normally associated with impact / shock sensors. At the heart of the JSS900 is a sealed capsule that utilizes a electret condenser element and a ball bearing. This critically tuned circuit then  picks up impact to the vehicle glass or body but does not false alarm from wind or interference from two way radios or cell phones. The sensitivity can be user adjusted to suit the vehicle being installed into and also for the amount of sensitivity required.