1. Nylon and fiberglass brushes are soft and flexible, suitable for cleaning jewelry, watches and coins 2. Insulated, can safely clean battery-powered devices 3. Can be used for a variety of purposes, pen brush removes rust and corrosion 4. Multi-function: suitable for circuit board cleaning, car rust removal, watch polishing, removing dirt and rust, removing car debris and scratches, etc. 5. It is recommended to turn it to a length of about 5mm for more convenient use 6. Note: only replacement head, not pen included
