If you notice the main valve failing to open or erratic fluctuating downstream pressure

this critical component is a direct replacement for the MET140 sight gauge protector

Contractors can perform non-intrusive calibration using the included magnetic wand

Durable Construction: Heavy-duty aluminum blades designed to withstand high-velocity airflow and outdoor exposure

Automation Components Inc (ACI) A/20K-D4-PB Thermistor 326058-758 If you notice the mainThe Automation Components Inc (ACI) A 20K D4 PB Thermistor is a high precision duct temperature sensor engineered for HVAC Building Automation and light industrial systems. This model features a 4 inch 304 stainless steel probe and a 20K Ohm NTC sensing element, providing an accuracy of + 0. 36F (0. 2C). Designed for rapid installation, the unit includes a flame retardant ABS plastic box enclosure with a built in mounting flange and a foam vibration