The Centerfielder makes it possible to balance twin engine charging systems by monitoring port and starboard regulators. When both alternators and regulators are working, the Centerfielder splits field current from the dominant regulator, enabling both alternators to work together to support a large single battery bank. For use with Max Charge MC-612 or MC-624 multi-stage regulators only. Includes fused power wires and installation instructions. Three-color LED screen. 30 amps. 4.8" x 3.25" x 1.5".