MSD 6M-3L Marine Ignition Box # MSD6564Ignition Boxes, 6M 3L Marine Ignitions, Capacitive Discharge, Digital, Rev Limiter, 6 18 V, Blue, Each Ignition Box Output: Capacitive discharge Circuitry: Digital Rev Limiter: Yes Timing Retard: None Data Acquisition: No CD Voltage Output to Coil: 535 550 V Current Draw: 0. 8 amps per 1,000 rpm Spark Output (millijoules): 135 150 mJ Minimum Operating Voltage: 6 V Maximum Operating Voltage: 18 V Length (in.): 7. 890 in. Height (in.): 1. 870 in. Width