This product is an example of Ethernet shield where it twits garage door status over internet.
1. Project Enclosure for the Arduino + Ethernet shield from amazon.
2. Arduino, in my case the old Diecimila. You all know and love the arduino, found online about 23$
3. Arduino Ethernet shield ~ 40$
4. GE Choice Alert wireless-control center
5. GE Choice-Alert wireless garage door sensor
6. Screw Terminal
If you want to know more in detail, refer to