U.S. "C" Class Submarines in Gatun Locks, Panama Canal

Front:
SUBMARINOS AMERICANOS CLASE "C" EN LAS EXCLUSAS DE GATUN, CANAL DE PANAMA 23B U. S. "C" CLASS SUBMARINES IN GATUN LOCKS, PANAMA CANAL 98570

Back:
MADURO ... I. L. MADURO, JR., 34.46 CATHEDRAL SQUARE, NEXT TO CENTRAL HOTEL P. O. BOX 281, PANAMA PANAMA HATS, SILKS, FRENCH PERFUMES, SOUVENIRS, ETC., ETC. FOR MESSAGE ONLY