We attached 3 extra pairs of carbon brush in this package. Carbon brush is consumable parts of all types of polisher. They need to be replaced when they are exhausted. Otherwise polisher stop working. Please kindly read the important remind (1)-(2) below. Important Remind (1): The pipe tube polisher in this package is NOT ONLY a pipe polisher, but also a powerful variable speed wet dry use polisher / grinder. It can work with all 5/8-11 thread abrasive tools (up to 5 Inch). Important Remind (2): Please also see the 7 pictures attached to see how to remover the aluminum frame for belt, and make it a powerful grinder / polisher. This package carries (a). Professional for burnishing, finishing and re-conditioning stainless steel, steel, non-ferrous metals, plastic & wood. Max: 270 degree wrap angle to do efficient result/work. Double gear reduction brings high cutting torque. This machine is variable speed, speed remains constant under load with.