同益股份：主要代理销售斗山PP、FCCL、NWB、硬板等材料，整体销售额占比不大

Group 1 - The company has established a long-term partnership with Doosan Group, primarily acting as an agent for the sales of materials such as PP, FCCL, NWB, and hard boards [2] - The overall sales volume and transaction amount related to this partnership are not significant [2]