This is a electric field coil made of 24V brown color copper material. It is used in 4.5KW starters, which provides reliable performance and supe;r safety under all operating conditions. Wurth is the only company that warrants all of their electronic parts to be free from defects (see warranty information on parts page) and offer industry leading turn-around times at our guaranteed best prices. For Sale Competitive price. Nickel plating Use in 4.5kW and 5kW startre coil. We can provide most precise dimensions and connectors as your requirements .its charge from the copper windings on the armature core, is magnetically attracted to the copper part of the electric field coil.