A delta lightning arrestor la302r helps to provide immediate, and reliable protection against the high voltage surge (such as that of a lightning strike) on your building or power lines. These units will last a lifetime, except in the extreme cases of rare excess surges. This particular type of surge is particularly devastating to electrical components, almost always rendering them useless. In addition, if you are not protected against high voltage surges, an electrical fire can easily be started within moments as a result of high current levels rushing through building wires. Your breaker box is incapable of providing protection against this "lightning fast" surge of electricity. By the time your breaker has switched off, the surge has literally already done its damage. Although a lightning arrestor helps to prevent high voltage spikes from infiltrating your circuits, it does not protect against the common smaller surges.