Chengziguan (Hanzi: 程子冠) is a type of guanmao (冠帽), a men's traditional hat originated in China, dates back to the Five Dynasties and Ten Kingdoms period. It's said that this kind of headgear was usually worn by Chinese Song Dynasty philosopher Cheng Hao and his brother Cheng Yi, therefore it's called Chengziguan, which literally means “the hat of the Cheng”. Chengziguan is made with horse hair.
Due to the influence from China, it was usually worn by men from the yangban, the upper class of the Joseon period in Korea (called jeongjagwan (정자관) in Korean). It was mostly worn at home as a daily headgear instead of a gat, a formal headgear in Joseon dynasty.