The ceiling-mounted XA601 arms with a four-digit code programmed by the owner. This unit uses passive infrared sensors to detect motion within a 360-degree area. When triggered it sounds a blaring 135dB alarm to protect your garage, home, caravan or business. Insert batteries, mount using the screws provided and enter your own four-digit security code; your garage is protected. A 15-second delay allows the user to enter the disarm code without triggering the siren. Once triggered, the siren sounds for 30 seconds before resetting.