Lubricant for ignition system contacts. It is applied on the internal rim of their protective cap or on the insulator near to the nut on the casing (but it must not be applied on the contact head because it is di-electrical). The lubricant is also frequently used on insulation of high-voltage wiring, end pieces of caps and ignition coils. Here it serves for increase of their resistance value (it is especially relevant if the wires are old and/or cars are used in wet climates). In the instruction for spark plug replacement, the use of such a protective lubricant is assumed each time and depending on the conditions.