天润工业：子公司生产及销售减速机壳体等，该部分业务产生的收入占公司营业收入比重较小

Group 1 - The company’s subsidiary, Weihai Tianrun Machinery Technology Co., Ltd., produces and sells components for reducers, specifically reducer housings and planetary gear frames [2] - The company is a parts supplier, and the revenue generated from this segment is relatively small compared to the overall revenue [2] - The company is unable to confirm whether its components are used in RV reducers [2]