The scratch brush pen can apply in many applications, the pen brush is good for tight place, electronic applications, removing rust. The fiberglass brushes are soft, good to your jewelry, watch and coin. The pen is insulated, feeling safe to your battery operated devices 3 kind of scratch brush pen in different materials, meet the and sanding needs of various scenario Twist end of the sanding brush pen to reach the desired length of bristles and stiffness as need.