The 20564 is a 12v 40 amp alternator, a new aftermarket direct replacement engineered to match the fit, form, and function of the original alternator. Specifications: - Voltage: 12V - Output: 40 amp Confirm exact fitment with your year, make, and model before ordering. Cross-Reference / Interchange Numbers: - Replaces / compatible with: 119128-77200, 1836-006-002, 1836-006-002-00, 1836-006-002-0B, 20564, GP9912, GP9914A. Why ePartsGlobal: specialist in heavy-duty starters, alternators, and charging-system electrical parts. Backed by a 1-year warranty, free shipping on orders over $19.95, and fast fulfillment. Ships from USA.