433mhz Wireless Door Sensor Wireless Vibration Detector Window Door Detector Magnetic Contact for Home Alarm System It will alarm when the glass shaken or broken; Send wireless signal to the alarm . The sensor is wireless vibration sensor, high sensitivity, with a slight vibration the sensor will send alarm signals to the host Input Voltage: 12V DC Work Frequency: 433MHz Transmit Distance from host:more than 80m(no obstacle) Power supply: Battery (not included)