https://www.vedardalarm.com/water-leakage-alarm-wireless-home-security-hb-brand-p-241

HB brand wireless compatible water leakage detector and wireless alarm
It is used for flood alarm for home and hotel, kitchen, bathroom or living room water detection. Easy installation with wireless connection to HB brand wireless alarm panel with app notification.
Totally sealed with waterproof feature.
The probe is with oxidation resistance.
Battery can be used for 8 years.

Technical specification
1. working voltage: 3.6V lithium battery
2. alarm current: <=50mA
3. standby current: <=10uA
4. working temperature: 0-50 C
5. Working relative humidity: 20%RH～100%RH
6. wireless emitting frequency: 433MHz
7. emitting distance: 300m at open area
8. dimension: 106×83×38（mm）