The Arm (OEM Part No. 3128309137) is a spare part compatible with Boltec-MC and Boomer-MD underground drilling rigs. Manufactured from high-strength alloy steel, it is designed as a structural component for the arm assembly position in hydraulic and mechanical linkage support systems. The arm provides reliable support, connection, and controlled movement for drilling rig assemblies, helping maintain accurate positioning and stable operation. Its durable construction offers excellent strength and resistance to mechanical stress in harsh underground mining environments. This OEM replacement arm ensures dependable performance, extended service life, and efficient operation for drilling and bolting applications.