The ADT Wireless Relay Module with Status LED lets you see if your alarm is armed or disarmed from anywhere around your home. Also, when you return home, you can see if the alarm is set or not. Then you can disarm it before you have a false alarm. This is a very convenient little device and easy to add.
The most common place people mount the ADT Wireless Relay Module with Status LED is in the garage, but you can also place it in other locations (as long as you can get power to it since it comes with an AC
Adapter). You should use it indoors only, but if you are feeling a little risky, you can also mount outside in areas with little weather at your own risk.