This pressure control switch is designed to regulate ammonia pressure in HVAC systems. It has a 12-inch long probe and can handle pressures up to 50 pounds per square inch. The switch operates on a double-pole, single-throw mechanism, making it reliable and efficient in controlling the flow of ammonia. With its durable construction and precise calibration, this pressure control switch is an essential component for any HVAC service technician looking to maintain optimal system performance.