This article may tend to give a misimpression. The device shown, a Flo by Moen Smart Water Sensor, is not a device that "can't do anything about" a leak besides warn you about it. Although the sensor probably can be used in a standalone way to give a leak warning -- I've never tried to use it that way so I'm not familiar with that functionality -- it's part of the Flo by Moen leak detector and water shutoff system. The shutoff valve is not a more expensive leak detector. It uses the same types of Flo by Moen Smart Water Sensors shown in the article's photos to activate the shutoff valve to turn off the home's water when a leak is detected. The sensors don't cost more than normal when used as part of the complete system. The automated shutoff valve does cost more -- several hundred dollars -- and will be professionally installed in most cases, as the article indicates. After having a near-disastrous flood after a plastic toilet fitting broke, I purchased the Flo by Moen system -- 16 Smart Water Sensors and the shutoff valve. I had a plumber install the shutoff valve. The system works well, and I feel much safer having it in place.