They are identical components

By utilizing 3-wire power-open/power-close dampers

two-pipe room thermostat designed for dual-temperature control in complex HVAC systems

The 1/8" NPT tapped drain allows for the safe piping of condensate away from the valve and equipment to prevent corrosion or water hammer

whereas this 750mv thermopile is a thermopile generator designed for millivolt control systems

Lennox 27K66 Burner 321894-706 They are identical componentsThe Lennox 27K66 Inshot Burner is an OEM replacement part engineered for high efficiency atmospheric combustion in residential and commercial furnaces. As a veteran grade furnace burner replacement, this component is designed specifically to withstand the thermal stress of high cycle heating demands. It effectively replaces legacy part numbers 27K6601, 65257000, and LX013, ensuring your system maintains its original factory specifications for flame