As a DIN connection solenoid coil

it is engineered for use with a cadmium spring to maintain high-sensitivity regulation in commercial gas equipment

the hyphenation is simply a variation in manufacturer labeling

Direct OEM Replacement: Verified 1:1 match for 621720R and 621300

providing the necessary 24-volt AC current to power contactors

Armstrong Furnace R44704-002 Induced Draft Assembly 30067439-890 As a DIN connection solenoidThe Armstrong Furnace R44704 002 Induced Draft Assembly is a critical OEM replacement component designed to maintain the integrity of the combustion cycle in high efficiency residential and commercial gas furnaces. This 1 20 HP, 115V, 3200 RPM motor works as a draft inducer blower, creating the essential negative pressure required to pull combustion gases through the heat exchanger and safely vent them through the flue. As an exact functional