This card is difficult to find. It is a 2002 Donruss Classics card of Herschel Walker, #125.
The thing that makes it special is the fact that these were only given out originally at the National Sports Collectors Convention that year, in Chicago, Illinois.
The cards were limited to a run of just 5, with this being the #1 example. It's very tough to see on the image above, but on the left side of the card front, just to the left of Walker's knee, there is an embossed mark. It shows: 2002, for the year, and under that, is a larger number, 23, which signifies that this was the 23rd annual National Convention.
Donruss did this a few years running. There is also a limited edition card from the Atlantic City convention held the following year.
As always, I'm pleased and grateful to add this card to the collection at the Herschel Hoard.