This Beckett Powerlight 120VAC Igniter is designed for use with AFII and AAF burners. It is compatible with a variety of brands and models, including the 51805U. This ignition control board is suitable for use in HVAC and refrigeration systems and is a reliable and durable component. Whether you are replacing an existing part or installing a new system, this Beckett igniter is a high-quality choice that will deliver excellent performance.