To prevent damage to your equipment from electric power surges and spikes.

Most other surge suppressors continue to let power through even after their circuits have been damaged, leaving your equipment exposed to future surges. APC's SurgeArrest fail safe, which means that once the circuit of an APC SurgeArrest has been compromised the unit disconnects equipment from the power supply ensuring that no damaging surges reach your equipment.

Protection of data lines (Ethernet, Coaxial and Phone lines) ensures complete protection of your equipment from surges. It is very important to protect your equipment from “back door” electric surges traveling through data lines, as they can be as damaging to your equipment as surges traveling over power lines.