This is an Allied Air Enterprises 60566 P-8-5813 dual-element time-delay fuse designed to provide overcurrent protection in electrical circuits. Rated for 25 amperes and 600 volts, it features a Class RK5 designation, indicating its current-limiting and high interrupting capabilities up to 200,000 Amperes Interrupting Rating (AIR). The dual-element construction allows it to handle temporary inrush currents from inductive loads like motors and HVAC compressors without nuisance tripping, while still offering rapid response to short circuits and sustained overloads. This fuse, which measures 13/16" in diameter and 5" in length, utilizes ferrule terminals for mounting in a fuse holder. It is commonly used in various applications, including HVAC systems, motor control circuits, and power supplies. Allied Air Enterprises is a Lennox International Inc. company.