To expand, as far as I can tell there is no physical difference. It does differentiate a purchase from a Wal-Mart or parts store from a dealer. It prevents people from trying to return the filter to a dealer for a refund since the price is a lot lower, Wal-Mart buys in a lot higher quantity than dealers. Also if there is an issue that might be a warranty claim, a receipt showing the part was purchased from a dealer is required.