Ultrasonic Sensor

An ultrasonic sensor triggers the alarm if a change in air pressure or movement is detected in the cabin of the vehicle. It does this by transmitting ultrasonic sound waves (like a bats sonar) around the interior of the vehicle. Because this is one of the best sensors for protecting the inside of the vehicle it is a good upgrade if you carry goods or have a large car. It is also recommended for vehicles where the windows can sometimes be removed intact, allowing access to the inside of the cabin without setting off other sensors. This includes Subarus (which have frameless windows) and vans. Note: because of how the ultrasonic sensor works do not leave animals or children inside the car with the alarm armed. You must also remember to always make sure all the entry points to the car, including windows & sunroofs are shut because air movement will trigger the sensor. This sensor can be added as an optional upgrade to any AVS alarm.