Lightning and power surges can permanently ruin your electronic equipment while changes in voltage can cause lockups and loss of work. The Professional SurgeArrest surge suppressor from APC protects your equipment from these threats as well as against surges caused by lightning faults and electro-static discharge. It also protects your equipment from 'back door' surges traveling through data lines which can be as damaging to your equipment as surges traveling over power lines. The Professional SurgeArrest surge suppressor has a Fail Safe Mode which disconnects your equipment from the power supply once the circuit has been compromised, ensuring that no damaging surges reach your equipment. It is ideal for high-end home equipment and business applications such as small office computers, high-performance stereo equipment, laser printers and modems.