Hollow Coin. 1950s-1990s, KGB. Hollow coins easily concealed microfilm and microdots. They were opened by inserting a needle into a tiny hole in the front of the coin.

Hollow Coin. 1950s-1990s, KGB. Hollow coins easily concealed microfilm and microdots. They were opened by inserting a needle into a tiny hole in the front of the coin.

Hollow Coin. 1950s-1990s, KGB. Hollow coins easily concealed microfilm and microdots. They were opened by inserting a needle into a tiny hole in the front of the coin.