A black wheel for the MINIRAIL is made from a conductive plastic material. It will be used when there has to be a complete discharge of static electricity build-up. Its resistance that is coefficient to electricity is 28,8 Ω/cm². When it comes to the normal black wheel with a carbon charge it is 5 x 10¹º Ω/cm². It is recommended that it be used in electronics when there is a need to avoid build-up of static electricity during electronic circuit boar manipulation, microchip etc, the technical characteristics here will vary as per the use. In Electricity it is recommended for use as it helps avoid sparks that come from static electricity when transportation is underway or if supply or manipulation in car batteries can lead to sulphuric acid contents being ignited. It also finds use in many plastic products where there is accumulation of static electricity, leading to sticking together of components.