This is a very cool example of a common die marriage, the O-107, but this one appears to be the "prime" meaning that it was struck before the die defect formed in the N on the reverse (the die defect is a key diagnostic for this marriage). So that makes this one considerably rarer than the common ones with the defect. It was also struck about 5% off center, but in looking at many other examples, that doesn't seem very uncommon with this coin! Image courtesy of Rick Irons.