The Moen Flo Shutoff comes in three sizes, 0.75 inch, 1 inch and 1.25 inch, and the size is set by the diameter of the main water line.
Each connects over Wi-Fi, plugs into an AC outlet near the pipe and can close the water supply on its own when it detects a leak.
Moen lists Alexa, Google, Ring, Alarm.com and NICE as compatible. Home Assistant has a Flo integration that polls the Flo cloud for the valve state, flow, pressure and temperature.
Moen's support site calls the Flo Shutoff the device formerly sold as the Flo Smart Water Monitor and Shutoff. The Moen Flo Detector is the leak sensor formerly sold as the Moen Smart Water Detector and Smart Leak Detector.