This historic commemorative stamp pair from Poland (Polska) celebrates the 400th anniversary of the Polish postal service, illustrating the evolution of communication from early horse-drawn postal coaches to modern airmail transportation. The 95-groszy stamp highlights a historic postal carriage, while the 60-groszy stamp features an aircraft symbolizing modern postal delivery alongside architectural landmarks. The set is valued by thematic collectors specializing in postal history, transport evolution, and European commemorative issues. Well-preserved examples remain popular additions to mid-20th-century Poland philatelic collections.