The Hubbell 15A male ungrounded Edison plug, also known as a NEMA 1-15P plug, is a 2-pole, 2-wire connector designed for applications where a grounding connection is not required. These plugs are rated for a maximum of 15 amperes and 125 volts and are commonly used on devices and appliances that are double-insulated, meaning they have a design that eliminates the need for a separate grounding wire. While not used in modern grounded installations, NEMA 1-15P plugs are compatible with standard NEMA 5-15R grounded wall outlets.