Blue Sea Systems VSM 422 Boxed Vessel Systems Monitor Includes-head unit, surface mount bezel, surface mount gasket, DC Shunt, AC Transform, Battery Temperature Sensor, connectors and screws Monitors DC systems-voltage, amperage, battery state of charge - amp hours remaining, time remaining, % charge, battery temperature Monitors AC systems-voltage, amperage, watts, frequency (alarms for voltage, amperage and frequency) Monitors tank levels-fuel, water, waste, (alarms for high level waste, low level fuel and water) Monitors bilge-active, cycle count and duration (alarms for cycles and duration)