The listing, Lincoln Cent Die Clash Error Lot of 20 Coins! has ended.
Die clashes occur when a coin is missing from the coining chamber and the hammer and anvil die hit or clash with each other. This creates an error in which elements of one side or the other or both are transferred to the opposite side of the coin. In the case of these, most are reverse clashes which show parts of the obverse portrait of Lincoln transferred to the open areas of the reverse bays of the Memorial. A few here are obverse clashes. It would take you months of roll searching, as it does me, to put together a set of 20 of these. Mailed correctly and shipped free.