Manholes have been widely used in road drainage projects in the municipal construction of Shijiazhuang City over the years (such as the elevated bridge water pipes on Peace Road, the elevated bridge on Huai'an Road, Construction Avenue, Sports Avenue, Yu Hua Road reconstruction, Zhonghua Avenue, Jianhua Avenue, etc.) and surrounding areas (such as Beijing, Baoding, Xingtai, Handan, Hengshui, Shanxi, etc.), earning high praise and trust from a large number of users.