What is the difference between 391937 and 391937/U

this upgraded heater provides the exact amperage draw and heat distribution required for peak cold-climate performance

Utilizing this Goodman certified part maintains the mechanical integrity of the electrical cabinet and ensures the inductive load remains within manufacturer specifications for long-term system reliability

this is the bracket only

The visible LED status indicator provides instant diagnostic feedback by confirming when the relay is activated

Johnson Controls SHL10A-603R Bulb Weather Shield Els PW 17895 What is the difference betweenThe Johnson Controls SHL10A 603R is a heavy duty bulb weather shield engineered to protect remote bulb thermostats and outdoor temperature sensors from the degrading effects of direct solar radiation and environmental exposure. Designed specifically for A19 Series Thermostats and A99B Series sensors, this bulb shield assembly supports both single and dual bulb configurations. By mitigating solar gain and wind chill interference, the SHL10A 603R