The most valuable of the series of brass samples of circulation coins of the communist era.
One of the two proofs complementing the 1949-57 brass proofs. Differing in form of execution, as the denominations introduced in 1958 (2 and 5 zloty) were not marked with a concave SAMPLE inscription, but it was placed on the stamp (as a result, it is convex on the coin).
Very rare sample.
Mint, in patina.
Brass, diameter 29 mm, weight 10.12 g.