1.metals shield anti-fire ABS2.connecting mode: N.C. normally closed3.rated current : 100mA4.rated voltage : 200 VDC5.operating distance: more than 15mm, less than 25mm6.rated power: 3WNo external power supply, connect to wired or wireless alarm control panel GND and N.C ports directly! Please note that this item not fit to iron door, It will decline magnetic of the sensor.