The SM 2051 is a heavy-duty 24-Volt Alternator Rotor (Armature Assembly) specifically designed for the Hitachi Zaxis 210 (EX 210) series excavators and "Funtoosh" style industrial alternators. Built to O.E. (Original Equipment) Specifications, this rotor is engineered for the 24V / 2-Pin regulator system, providing the high-torque electrical performance required for heavy earthmoving and construction machinery.