Door alarm employs distant controls to set protection code for arming/disarming; home safety process complete with completely programmed key device and sensors, later if you need to Do-it-yourself, please factory reset initially In accordance with guide, then pair them all over again or search operation movie on YouTube "KERUI Standalone https://www.firesense.co.uk/type/conventional-fire-system/conventional-fire-alarm-control-panels/