I have one I bought off Amazon a few years ago. Still works great but like the other poster says, you have to keep the water level just right. Mine has a remote alarm too that you can place in a room a ways from the pool. I never had to use the remote alarm because the pool alarm is ear piercing. Please also remember that pets can’t easily get out of pools either. I also installed two pet ramps at the opposite corners from the stairs. Pets get confused when they fall in and may swim against the wall until they run out of energy and drown, never making it to the steps. I have an indoor pool and so far this alarm and the addition of two pet ramps has saved my cats from drowning. The steps fold out when not in use and are anchored in the concrete by drilling two holes.