GPS Ankle is a professional tracking product designed for community correction, parole, residential surveillance, Alzheimer's, mental patients and other special industry tracking applications. It includes GPS ankle, Curfew base station (optional) and management system. The GPS ankle collects GPS/Beidou/WiFi/LBS tracking information and uses the 4G wireless network to send the tracking information to the server to track the ankle. The ankle has a built-in conductive circuit, which will alarm immediately after disassembly. The ankle also has a built-in UWB high-precision ranging module (optional), combined with the Curfew base station, up to centimeter-level ranging accuracy, to determine whether the tracked target is in the designated area. The Curfew base station also has a built-in UWB high-precision ranging module. Once the distance between the ankle and the base station exceeds the preset threshold, the system will immediately alarm. The base station has a built-in motion sensor. Once the base station is moved, the system will immediately alarm.