MARINCO Reverse Y Adapter, (2) 30A 125V Males to 50A 125/250V FemaleThe Reverse "Y" Adapter has two male plugs with special power isolation circuitry for added safety. When one plug is connected to a receptacle, the circuitry isolates the second plug. The reverse "Y" provides 50A 125/250V power when only two 30A 125V receptacles are available.Note: Reverse "Y" will NOT work with 50A, 125V, 3-wire inlets. Power is provided in both circuits to the 4-wire inlet, but the dock side receptacles limit the current in each circuit to 30A. The two 30A 125V receptacles must be supplied from a single power source providing from 208V to 250V between them for proper operation.Boat Side: Female Connector 50A 125/250V w/Sealing Collar System Attaches to boat inlet or cordset Dock Side: Male PlugÀšÂ 2-30A 125V Locking Attaches to dockside receptacle or cordset