The Von Duprin alarm kit is a simple yet effective way to deter unauthorized use of an opening. While the exit device is still a means of egress, the alarm kit contains an internal horn. When the touch bar is depressed, the horn sounds to provide an audible means of signaling that the opening has been violated. The alarm kit can be armed or disarmed by key thus allowing the exit device to be set in an armed or disarmed mode. The horn is rated at 85 decibels. Smooth cover. Includes a 6" x 20" decal for application on door "EMERGENCY EXIT ONLY. ALARM WILL SOUND." The key switch uses a standard 1 1/4" (32mm) mortise cylinder with a straight cam (Schlage 20-001, B502-191 cam). The unit operates on one standard 9-volt alkaline battery. When the battery is weak, the horn will emit an intermittent low battery alert signal. The alarm can automatically re-arm with a 1 1/2, 3 or 6 minute time delay upon request.