Review on Honeywell Ademco 958: Advanced Overhead Door Contacts for Enhanced Security by Ben Cooper

Installed in the top center of the garage door, it works well. I set it up so that the green light on my control panel doesn't come on until the garage door is closed, so I can see at a glance if the door is open or closed (assuming no other zones are open). The downside to this is that the garage door has to be closed when I set the alarm, which is a bit of a hassle. I can install it remotely over the internet, so that's an option as far as I remember. Installation was easy, the magnet is strong and works upside down (on the wrong side of the mount).