Very nice, with a natural sheen. From the end of a sheet metal. In a nice patina.
The first type of Polish halftails - with an eagle on the obverse instead of the shield of the coat of arms.
The second variant of half-tracks with the Eagle, with the denomination in the shield specified in half-pennies (3) instead of the fraction of a thaler (Z4).
Variant with RE POLO on the reverse (instead of REG POL) and the date numeral 4 stamped on the letter M.
Rare.