Size: 8*3CM Water sensor and alarm all in one Easy to use near water heaters, sump pumps, under sinks and toilets. Power supply: DC9V battery (not included) Alarm decibel: 90db Features: Unlimited use spot detector; easy to re-use for reuse Easy to use near water heaters, sump pumps, under sinks and toilets. Water Detector and Alarm: The most economical way to protect against water leaks in different places in the house Loud sound alarm Economical way to defend against water leaks Specifications: Alarm decibel: 90db Power supply: DC9V battery (not included) Size: 8 * 3CM Test method: Place the water leak alarm on a wet towel, the product will emit a warning sound. Remove the product from the wet towel, the alarm stops.