Folding Bianchi Bike - WDYT?

I found this on a local CL and I'm intrigued by this yellow thang. It's still available but the guy doesn't know what frame size it is. How do I describe to him how to measure it?

http://wausau.craigslist.org/bik/734843874.html

Folding bikes generally don't go by frame sizes. I can't tell from the photo if the wheels are 16" or 20". It needs a little TLC, but if you are a folding bike enthusiast, it could be fixed up and be a sweet little bike.

You might want look at the Folding Bikes section of Bike Forums (www.bikeforums.net).