Self-exciting 1-wire Alternator. Optional when converting Generator to an Alternator or an externally regulated to an internally regulated Alternator.The 89017781 Alternator - New, 12V, 63A, 10SI, Aftermarket Delco Remy fits equipment brands such as: Allis Chalmers, Case, Cockshutt, Gleaner, International, John Deere, Massey Ferguson, Minneapolis Moline, New Idea, Oliver, White