Shop name:Chong Qing Shuo Yue Ke Ji You Xian Gong Si Replace it 60 hours, otherwise the electric rotating tool will overheat. Carbon brush, suitable for carbon brush, used for electric knife sharpening tool 3000,200. installation : Step 1: a wrench to open the carbon brush cover. Step 2: Take out the carbon brush. Step 3: Replace the carbon brush with a new one. Step 4: a wrench to lock the lid firmly. Note: These brushes should be replaced 60 hours. Size: about 4.8x4.8x10mm Application: Suitable for 3000, 200. Colour:Photo Color Material:carbon + metal Package Contents: 2 x Carbon Brushes Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.