When I originally went to the Apple Developer Site to update my iPhone / iPad devices to iOS 7 GM (Gold Master) I quickly discovered that I didn't know my model number. The downloads page looks like the following:
So what's a developer to do?
There is several ways to find your model number but I've found this site to be the absolute best as it shows more than just the model number. The site is :
They ask for your serial number so be warned if you are afraid of that kind of thing. But the end result is this page of information:
After looking at this page I would download the A1428 build for iPhone 5.
This obviously work with other Apple products besides iPhone. I was able to look up my iPad and other devices. I hope someone finds this as helpful as I did.