To use, simply insert a 9 volt battery. Connect to your pad, floor mat or seatbelt, (sold separately). Place the pad, floor mat or seatbelt in the location you have chosen. When your patient sits on the pad, the alarm will beep twice to let you know it is activated. When they take their pressure off the pad, the alarm will sound. If you use with a floor mat, the alarm sounds when they step on the mat. If you use a seatbelt in a wheelchair, the alarm sounds when they release the seatbelt, giving you valuable time to get to their side.