Wet Call Alarm is a proven way to alert the caregiver when incontinent patients wet the bed. Perfect for both hospitals and nursing homes, this compact alarm sounds an audible alert as soon as the bed pad sensor detects moisture. Promotes skin care and helps reduce infection. Alarm is easy to use just place the large, 18-1/2" x 24-1/2" pad under the bed sheets and plug it into the included alarm box. Portable alarm is powered by a 9V alkaline battery.