Product model: FST100-2020D product features: manhole cover management; Status monitoring; Alarm positioning; Alarm handling; Alarm inspection; SMS or email reminders; Maintenance settings; Map display; Text display. Application scope: The manhole cover sensor (ultrasonic liquid level) uses ultrasonic technology, NB-IOT communication technology, and 2.4G communication technology to automatically obtain local weather forecasts, adjust collection frequency and warning values, and achieve real-time monitoring of manhole water level. Management departments can monitor the water level of manholes in real time through intelligent manhole cover monitoring cloud platforms, mobile apps, and other methods, effectively predicting the health status of drainage websites and providing decision-making basis for flood control and waterlogging prevention.