One of the rarest Olkusz trojak.
A trojak distinguished by the initials of the mintmaster Kasper Rytkier (CR) placed in the obverse rim, above the royal crown.
Being the only stamp with these initials among dozens of stamps of the Olkusz mint.
An important and, above all, very rare type.
In the Onebid archive only one listing, of this piece, and that from 2010!
Attractive state of preservation.