Blue Sea Systems M2 Vessel Systems Monitor One Size. DC System Monitoring (up to two batteries)One input monitors the DC voltage state-of-charge current for one battery bank and another input monitors the voltage of an additional battery bank. Alarms include high and low voltage high current and low battery. AC System MonitoringThe VSM monitors a single AC voltage current and frequency. Alarms include high and low voltage high current and high and low frequency. Bilge & Tank MonitoringThe VSM has two inputs that can be configured as a bilge or tank monitor. When configured as a bilge input monitoring functions include pump active cycle count in the last 24-hours average cycles in a typical 24-hour period and total cycles. High alarms can be set for both the minutes of run time in the last hour as well as the number or cycle counts in the last 24-hours. When configured as a tank input tank status can be represented in both capacity (gallons or liters) or as a percentage of capacity. Custom tank shapes can be auto-calibrated or programmed. Both high and low level alarms can be set for all tanks. Specifications for Blue Sea Systems M2 Vessel Systems Monitor: Manufacturer: Blue Sea Systems Color: Black Package Contents: Blue Sea Systems M2 Vessel Systems Monitor Blue Sea Systems 1850: 1850 M2 Vessel Systems Monitor One Size