219-3-4788-4 is a hydraulic magnetic circuit protector from the 209/219/229 series, designed to combine power switching with accurate, reliable circuit protection in a compact unit. It features series trip configuration where the sensing coil and contacts are in series with the load, providing conventional overcurrent protection while simultaneously functioning as an ON-OFF switch. Multi-pole versions include an internal trip bar for common-trip construction, opening all poles in the event of an overload in any pole. The unit is available with various terminal styles including screw terminals, stud, or solderless connectors with front or back connected options. Common applications include branch circuit protection for EDP equipment, air conditioners, panel boards, and lighting controls.