This product works great. Loud beeping sound does alert when any moisture makes contact between the two sensors. It has saved me many times with my clothes washer leaking. Simply put it on the floor and it works. Note, that this unit will measure moisture that is on the surface as it makes contact with whatever you put it on. This is better than some units that are raised up 1/4 inch or so. The only bad comments I have are the two sensors tend to get a small amount of rust on them after a while. A little sand paper solves the issue. The other item that drives me nuts, you need a screwdriver to replace the battery 9volt. Summary-two negatives are no big deal as the alarm works great.