Direct Replacement: This unit is the exact functional equivalent for the PRS1011

it must be manually depressed to close the circuit again

High Environmental Tolerance: Designed for demanding mechanical rooms with a wide operating temperature range for consistent HVAC actuator resistor board performance

and various HFC/HFO blends

Durable Construction: Heavy-duty 2-tube stainless steel design resists oxidation and thermal fatigue in high-heat environments

System Sensor D4S Detector Sensor 30067439-890 Direct Replacement: This unit isThe System Sensor D4S is a 4 wire photoelectric duct smoke detector sensor component designed specifically for integration with the D4120 duct smoke detector housing. Engineered for high performance HVAC smoke detection, this replacement sensor head utilizes an advanced optical sensing chamber to detect combustion particles across a wide range of airflow speeds. It is optimized for low flow duct smoke detection, maintaining reliable operation in