A surg protector, also known as a surg strip or surg suppressor, is commonly a 6-outlet stip with built-in protection against over-voltage. Surg protectors do not protect for the under-voltage condition. Some surg protectors have an electronic component called a MOV (METAL OXIDE VARISTOR) which protects the computer or devices that plugs into one of the outlets on the surg strip. The MOV, however, has some drewbacks. If a large surg occurs, the MOV will take the hit from the surg and be distroyed, which is better than damaging the computer. However, with smaller over-voltages. each small surg weakens the MOV. A weaken MOV might not give the proper protection to the computer if there is a bigger surg. Also, there is no simple check for the MOV's condition. Some MOV's have indicator lamps attached, but this lamp only indicates when the MOV is destroyed. not when its weakened. However, having an indicator lamp is better than nothing at all. Some surg protectors also have replaceable fuses and/or an indicator lamp for the fuse.. Surg protectors have two features to consider when selecting one. CLAMPING VO:TAGE is thew voltage level at which the surg protector starts protecting the computer. CLAMPING SPEED is how much time elapses before the protection begins. Surge protors can not normally protect against power spikes (over voltage for a short duration) because of their rated clamping speed. Another feature to look at is the JOULE DISSIPATION CAPACITY. the greater the joule dissipation capacity, the more effective and durable the surge protector is. A surge protector with 630 joules of dissipation is more effective than one with 210 joules of dissipation.. Another feature to look for in a surge protector is how fast the surge protector responds to an adverse condition. Surge protectors that respond within Picoseconds (trillionths of a second), freact faster than surge protectors that respond in Nanoseconds(billionths of a second). Also, for greater surge protection choose a lower Transient Voltage Suppressing (TVS) Rating. A 330 TVS-rated surge protector is better than a 400 TVS-rated surge protector.. Surge protectors are not the optimum protection for a computer system because most available provide very little protection against adverse conditions. Even the good ones only protect against over-voltage conditions.