This series was issued on 20 August 1944 to support the Croatian Labor Service.
MiNr. 162-164 were issued in three perforation varieties (A: K 12.5, B: L 14.5, C: L 11.5), and MiNr. 165 in one perforation variety (A: K 12.5).
MiNr. 162-165 were printed in 3×3 sheets with 8 stamps and 1 label. MiNr. 166 differs from MiNr. 165 in color, and was issued in a souvenir sheet with the single stamp.