Product Features: The auto rubber pen is produced as a pen that writes on all rubber cheeks. Rubber is a rubber writing item made of quality real paint that can be used on plastic. It is white. Application: There is a mechanism that works by shaking in the metal case. Shake the pen thoroughly to get the wick wet. Press the wick end for a while and wait for the paint to flow. Pass over the text until you cover it. It has a lasting effect for a long time. Rubbing the rubber cheek into areas such as pavement may cause the paint to deform early.