The Door Alarm wedges under doors and windows, monitors for unwanted entry and activates for five seconds with a high pitched sound when a door is opened and triggers the alarm. The alarm is great protection for your home, hotel rooms or recreation vehicle. A hook and loop adhesive pad grips carpet, floors and windows. Alarm sounds for 5 seconds. The door and window alarm is powered by one 12-volt battery (included.) One-year limited warranty.