Ci-A01 UWB tag is an important part of proximity warning system, it’s used for employee wearing during working time, tag is based on UWB technology for accurate distance measurement, it’s designed with alarm button, buzzer and vibration. When people who wears tag going into the dangerous area set by uwb station reader installed on vehicle, tag itself will give buzzer and vibrate alert to user, to remind dangerous and so user can go away from the area, to assure employee safety during work time. It is used with Ci-D01 station reader to assure safety in factory, warehouse and construction field etc.