Amazing little device. It stopped bedwetting in my 8 year old boy who has NEVER had a dry night in 6 weeks. The first 3 weeks were painful as I had to wake him up and he just wouldn't get up on his own till one night, out of the blue, he woke up by himself and has never looked back since.
The system works well, very well, simple to operate and compact. It's loud and you cant really miss it. The sensor however should be dried before use. I figured out that shaking it in my hand helps. I highly recommend this Shield Alarm.