Four Chinese characters - Canh Hung Tong Bao / Cong below hole. 23.5mm, 3.00 grams.  Hartill 25.29 var.; Krause KM66 (C1.6h); Vietnamese Coins (2002) #-.

Lê Hiển Tông (r. 1740–1786) was one of the longest-reigning emperors of Vietnam’s Later Lê dynasty, ruling during a period when real power was held by the Trịnh lords in the north. His reign is often seen as the last relatively stable phase of the dynasty before the Tây Sơn uprisings. Although politically constrained, he oversaw a flourishing of Confucian scholarship and court culture. His later years were marked by increasing disorder, setting the stage for the collapse of Lê–Trịnh authority soon after his death.