First one of these I've seen outside the catalog, but have seen a couple of older XS800s. Great color, I'd love to have one but this one is too small. It's listed as 19" which would make it a 50 or 52, but by the standover it's a 54 cm. Hopefully the seller will clarify the size.
https://www.ebay.com/itm/Cannondale...241910?hash=item2162c8b6b6:g:w8AAAOSw3ORdXJHe
https://www.ebay.com/itm/Cannondale...241910?hash=item2162c8b6b6:g:w8AAAOSw3ORdXJHe