The Smart Water Shutoff provides protection against the larger issue of supply line leaks, while Smart Water Detectors will sense floods, water spills and drips, and drainage-related problems. When used together, the Smart Water Detector will communicate with the Smart Water Shutoff to turn your water off if liquid is detected for maximum protection against water damage.
The Shutoff is installed on the pressurized, supply-side of your home, with daily health tests, and automatic shut-off. It is designed to catch 80% of the water damage issues that occur caused by water coming into your home, through your supply line. The other 20% of water damage issues occur due to water coming out of appliances, through drains, and weather-related issues. The Detector catches these issues. They are designed to serve as a type of "belt and suspenders" to the Shutoff, for places like a water heater. BUT, they are also environmental sensors.
They can be used around leaky windows or in a basement corner to look for liquid, humidity changes, and/or temperature changes. These additional sensors add another level of security. They can be used together or separately, depending on use case and need.
Some examples of Detector use cases:
Attach the Leak Sensing Cable and throw the Detector in a boat to monitor for leaks during cold storage
Place the Detector in a drafty guest bedroom
Place under an old sink
Install in a wine cellar to monitor humidity