The Supco ES1024STL Sail Switch with metal plunger is a reliable airflow sensing device designed for HVAC systems. It detects the presence of air movement within ducts and activates or deactivates connected equipment accordingly. Commonly used in furnaces, air handlers, and ventilation systems, it ensures safe and efficient operation by verifying proper airflow before system startup. Its durable metal plunger enhances longevity and consistent performance. This switch helps prevent overheating, improves system safety, and supports energy efficiency by ensuring components operate only under proper airflow conditions.