Where are the serial numbers on a schwinn twinn?

The serial number on a Schwinn 220 recumbent exercise bicycle is located on the underside of the rear stabilizer bar (the short bar underneath your seat). You have to tip the machine on its side, and you will see a white sticker with a small grid and several numbers printed on it, and that's where your serial number can be found.

Yeah, I know... most difficult to access spot on the whole machine... of course!!