Both will offer a duty standby assist pump operation. With the Duo each pump will operate independently, the pumps float arm position causing the pump to start and stop. If one pump should fail, fluid would overflow into the adjacent tank, the other pump would then be activated by its float arm. This configuration does not require a control panel. The king has both pumps in a single tank, separate floats control the operation of the pumps via a duty standby, assist control panel. The panel will also cycle the lead duty pump. Both systems are fitted with alarms with BSM connection.