韩建河山：公司在河北地区主要销售RCP产品，其主要用于城乡市政、住宅小区等排水工程

Core Viewpoint - The company, Han Jian He Shan, primarily engages in the production and sales of prestressed concrete cylinder pipes (PCCP) and reinforced concrete drainage pipes (RCP), with a focus on the RCP products in the Hebei region [2] Group 1: Company Overview - The company specializes in the production and sales of PCCP and RCP [2] - In the Hebei region, the company mainly sells RCP products, which are utilized in urban and rural drainage projects [2] Group 2: Financial Performance - The sales revenue from RCP products in the Hebei region accounted for 3.54%, 2.80%, and 1.41% of the company's total revenue in 2022, 2023, and 2024, respectively, indicating a decreasing trend over the years [2]