Inductance coils (usually inside the RJ45 jack itself) are what provides isolation. They are made from very thin wires so if something goes wrong this is the fi

Inductance coils (usually inside the RJ45 jack itself) are what provides isolation. They are made from very thin wires so if something goes wrong this is the first and hopefully only thing that will break. If you apply enough voltage of course you can break things beyond this.