Xonic 5L use ultrasonic for flow and operate 8 years with inner batteries. It has no moving parts and maintenance free, and it has inner datalogging functions to save flow data. Also, it has RS-232C communication for remote data collection.
no moving part
accuracy 2%
fully digitalized
same size with turbine watermeter
8 years operation with batteries
stainless steel 304, no corrosion
insertion ultrasonic transducers
transit-time type