This soft grayish earthenware jar with a thick, double-layered mouth was made of very fine clay. Pottery jars with a double mouth date back to the late third to fourth century, and have been found in areas along the west coast of Korea in Chungcheong-do and Jeolla-do Provinces. Based on their approximate production dates and excavation sites, it is presumed that they originated in Mahan and were disseminated to adjacent areas.