Review on Protect Your Belongings with Wireless Water Leak Sensor Alarm - WER 90db Loud Buzzer, Longer Alarm Detection (Battery Not Included) by Arun Berry

These alarm clocks have saved my life many times. I have to use a hose to fill our washing machine. Sometimes it comes off etc. I have at least 4 of these on the floor next to the washing machine. The more alerts you have, the less likely it is that you won't get an alert due to bad battery etc. The more alarms you have, the louder it is too! Also, I highly recommend using a magic marker to mark on the outer edge of the base where the alarm's "speaker" is located. Then when you screw on the top, make sure the speaker hole is aligned directly over the "speaker". This achieves the highest possible alarm volume. If it is offset, it will be significantly muted. Then extend the mark from the bottom to the top of the side of the case to align the two lines perfectly every time!