Water sensors are small devices that can alert you whenever water is present around the refrigerator, the washing machine, sinks, and toilets—even in the basement. If you've got a leaky basement or appliances of a certain age, a smart water sensor makes for a strategic addition to your home.
Some smart water sensors work alone via Wi-Fi, and others connect to a smart-home hub; when wetness occurs, both can send a message to your phone so you can respond with a towel or a plumber. The units we're talking about here can't actually shut off the water; they simply alert you to the danger so you can respond quickly.
Though you can get a leak sensor that will set off an eardrum-piercing tone for as little as $10, if you want to get alerts and remote access, be prepared to pay a bit more. But the money is well worth it - an average water damage claim can easily cost $2500.