Most mint errors that are double struck are found with the second strike off-center. In-collar double strikes are scarce and so are flipover double strikes. This Indian Head Cent mint error is unusual since it is both a flipover and double struck in the collar.
This 1901 Indian Cent is a flipover double strike. It is very dramatic since much of the detail from the second strike is visible on both sides. Flipover errors are highly collectible since you are viewing both designs on the same side of the coin.