International letter with perfin “N.L.” in the stamps. The letter is franked correctly with 40 øre, which was the rate for international letters from February 1st 1921 to October 31th 1925. The stamp is cancelled December 17th 1823 with a whole letter cancellation stamp Tp. SP 4B. K K.3 Bro IV. This letter is the first of only 2 known proves for the user of N.L. The 2nd is also in my collection.