Cord Grip Connector, 1″, Aluminum for Cord 0.450″ to 0.560″
https://nsiindustries.com/product/cord-grip-connector-1-aluminum-for-cord-0-450-to-0-560/
Use the Bridgeport 1″ Aluminum Cord Grip Connector for Portable Cord Range 0.450″ to 0.560″ with NPT tapered threads and either a polyethylene or polypropylene gasket to create watertight protection in indoor and outdoor applications.