The BASO Gas Products Y75AA-3 Flame Sensing Probe is a safety component designed to detect the presence of a flame in gas-fired HVAC equipment. It works by sensing flame rectification, sending a signal to the control module to confirm proper burner ignition. Commonly used in furnaces, boilers, and rooftop units, it ensures safe operation by shutting off gas flow if no flame is detected. Its reliable performance enhances system safety, prevents fuel hazards, reduces downtime, and supports efficient combustion control in heating systems.