My 99K had them, a bit like two small size AA batteries. When I had my machine rewired they just removed them. Apparently we don't need them today, radios and TVs aren't affected by the sewing machine like they used to be. It has nothing to do with the function of the motor or the running of the electrical parts in themseves. Maybe if you listen to a very old radio with tubes while you sew it might interfere with the signal a bit;- )