This is a Brand New-in-the-Box Beckett Interrupted Ignition Oil Primary CONTROLBOARD. Becket Model is 7455U (also R7184A1075 & R7184A). The Intertherm/Nordyne/Miller Part # is 624629. Thanks for looking and good luck!
The control board is the "brain" of your unit, coordinating and executing the operation of other various components by sending voltage when and where needed. A control board is constantly monitoring sensors and safety switches in the unit.