Subaru NGK FX58
NGK Resistor Spark Plug Wire Sets utilize a construction method known as variable pitch wire winding to create resistance to radio frequency interference.
The variable pitch winding (loose/tight/loose) provides suppression throughout a very wide range by scrambling and breaking up the electrical waves radiated by the firing of the spark plugs.
A ferrite magnetic layer consisting of a mixture of rubber, plastic and powdered ferrite magnetic materials, offers uniform resistance and unsurpassed conductivity. NGK wires have a lower resistance than conventional carbon core wires (8k ohm/meter versus 16k ohm/meter). This comparison is important to remember when you consider that many manufacturers recommend wires be replaced when the resistance exceeds 20k ohm/meter. This does not leave much margin for wear when the wire may only meet original standards at the very early stages of its life.
Ref ID: NGK-8691