Q: How to identify a recertified ipad?

The refurbished units come in a brown or black box, the factory new only come in a white box.  Some of the refurbished units have a serial number ending with an X.

There is no way to tell.

You can see the model number in Settings>General>About>Model. The model number has a two-letter code, a number and some more letters. The last part stands for the country/region. The first letter can be "F" (refurbished), "M" (normal retail), or "P" (personalized / engraved). For example MC605B is the model MC605 and B is for the region.

 Cheers, Tom

Most places have laws against selling something that has been opened as new.

That's why they call it an open box item and not new.

It is the wild west of eBay.

That comes up as iPad with Retina.  Since it is open-box, it will be impossible to tell if it has actually been used and then restored to factory settings.  As deggie said, the eBay is like the wild west...anything goes with very little policing of activities.

Was teh seller commercial or private citizen?  Do you have info on the original date of sale of the item?  Did you get any kind of warranty information for it?  These are all questions to be of concern to you.  You might try stopping by an Apple store genius bar and see what info pops up in their system about the iPad and ask if you have warranty coverage on it.