This bronze mirror has a three-stringed knob at the center of its back, a characteristic feature of mirrors dating back to the Warring States Period. The Chinese character “山” (pronounced “san,” meaning “mountain”) is inscribed four times around the center, and heart-shaped petals are inscribed between the characters. There are mirrors containing three, four, five, and six characters of “山,” and those with four characters of “山” called “sasangyeong” (four-mountain mirrors) have been unearthed more than the others.