This is the Starline MS-06BT Wireless Multi Function Sensor for use with the Starline E9 system.
StarLine MS-06BT wireless magnetic sensor (reed switch, 3D shock tilt movement sensor)
This sensor is battery operated and communicates with the Starline E9 via Bluetooth. The sensor provides a magnetic contact switch, a 3D shock, tilt, and movement sensor all built into one device.