Sits behind the washing machine or under the sink and sends a phone alert the moment it detects water. Loud local alarm, year-plus battery life, no wiring.

Key specs • Detection: water contact between the two probes • Alarm: 80dB local siren plus phone alert • Battery: CR2032, roughly 12 months, low-battery warning • Size: 5cm, fits behind an appliance • Requires: Zigbee hub

In the box Sensor, battery installed

UK notes The place to put it is under the washing machine, under the sink and by the boiler. A slow leak found in an hour instead of a week is the difference between a wipe and a floor.