Wen Rotary Tool Brushes The Wen 2305 is supplied with a set off replacement brushes so you can ensure the tool is running at its most efficient. You must follow the enclosed instructions to ensure that you complete the replacement correctly. Motor brushes are an important component as they will support the transfer of electric current between he stationary part and rotating part of the motor. As they get worn the performance of the motor will get worse. For more detailed information about rotart tool brushes checkout http://rotarytoolsguide.com/