Your security system may sound an alarm if motion is sensed, but why not prevent intrusions entirely? The Window Bug is a glass breakage detector, which triggers your alarm system upon the sound of breaking glass. Each Window Bug will protect up to 32 square feet of glass surface. A patented switch is installed inside the Window Bug. This switch is tuned to the vibration frequency of breaking glass and will momentarily open or close, depending on the application, to signal an intrusion. Normal shocks and sounds are ignored and have no effect on its operation, so you won't need to fear false alerts. Your alarm panel or system must be a fast-acting initiating circuit, with a response time of 20 milliseconds or faster. If you're not sure, just install a Pulse Stretcher (sold separately) to ensure that the system sees the Window Bug's momentary "broken circuit."