Technological trial in cupronickel of the unrealized circulating version of the ten with Henryk Sienkiewicz.
A coin of Stanisława Wątróbska-Frindt's design, which, despite reaching the trial minting stage, lost out to designs with Mickiewicz and Prus, which went into circulation a year later.
Minted variety in hard alloy (the inscription of the trial arranged differently than on nickel trials).
Very rare.
Mintage of only 20 pieces.
