A very rare denomination of the "three brothers" one-coin coin.
A variety without decorations on the obverse and with the characteristic narrow Eagle on the reverse.
In Marcin Grandowski's catalog "Common Minting of the Three Brothers" the rarity grade is R7+, which means 5-6 pieces known to the author.
Piece doubly struck on the reverse.
A very nicely preserved piece with fragments of mint luster, especially for this type of issue.
