Your Dometic MagicSafe MS 680 car alarm offers plenty of upgrade options. Up to 55 sensors can be added, including this radio infrared motion sensor. The useful Dometic MagicSafe MS-RMS radio motion sensor monitors the area outside your vehicle to scare off potential intruders. It can also be fitted inside to monitor the living area. The wireless design simplifies installation, so you can add one or several motion sensors with little effort.