This is a 2 coin set of 1997-P Roosevelt dimes, with one certified by ANACS and the other not certified but accompanying the coin in a 2x2 flip. The coins fit together to form a single coin. They are a mated pair set.
Probably the top layer was manually removed after the coin left the Mint based on the damage to the outer layer. There is a pattern of "copper" inside of the outer layer, which matches the other coin, and so they are definitely a mated pair set.
Raw Coin: UNC details on the raw coin with some bends in the outer layer.