Ensure optimal performance of your electric motors with our Medium Coarse Brush Seater and Commutator Seating Stone Multi Pack. Designed for both seating new brushes and cleaning commutators, these stones effectively remove carbon buildup and smoothes imperfections, promoting efficient electrical contact and reducing sparking. Maintaining the motor's commuatator and seating brushes correctly will effect your motor's performance. If your commutator is covered in carbon dust, or the brushes do not make full contact use of the stone will will immedately improve proformance under normal conditions.