Unsurpassed to hedge campers and coaches. The sensor is an ultra-low-frequency sensor that uses advanced electronic circuits in order to open all the doors, the trunk, the smashing of glass, the penetration into the interior and other types of penetration, without the use of contact switches or additional sensors perceives. This sensor measures the air pressure in the vehicle interior and the air pressure outside of the vehicle. If the air pressure in the vehicle change (opening of a door, flap or window), this sensor would trigger the alarm immediately. This sensor has no moving components and is completely insensitive to temperature changes, magnetic fields and radio waves.