The Chongtong was a term for military firearms of Goryeo and Joseon dynasty. The size of chongtong varies from small firearm to large cannon, and underwent upgrades, which can be separated in three generation type. The well-known "Cheonja", "Jija", "Hyeonja", and "Hwangja" were named after the first four characters of the Thousand Character Classic in decreasing size, thus making them equivalent to Cannons A, B, C, and D.
A page of the Korean Kukcho Orye-ui (ca. 1474) showing an early type of hand cannon (chhung thung or chongtong) and the bolt-like arrow and metal fins which was shot from it.