[ricosuave]

It's probably a transient voltage suppressor. Supposed to "clean up" the voltage so your devices can use them more efficiently.

Most devices are designed to run on a wide range of voltages ie. light bulbs usually are rated 110v to 130v. The higher the voltage the less a device needs to work.(like having a water pump rated at 120/240 volts. If you hook it up as 240v, it will consume slightly less than half of the same amount as one wired for 120v)

On my house(the one that we just finished in May 2006) I installed a variable buck/boost transformer after my outside main breaker but before my lighting panelboard. The local power company supplies around 120volts(this varies greatly from minute to minute). The transformer allows me to choose the operating voltage while producing consistant/regulated voltage(for me this is 130 volts). I have not had to replace even a single light bulb yet. Varying voltage will shorten the life of almost any device(even some with built in"surge protection" or power regulators). The biggest benefit of this transformer is that I get to use the power company's "dirty" power at a rate of nearly 130% efficiency

There are other ways to accomplish this that are not so extreme. When you purchase anything electrically driven(bulbs, tv's, etc..) look at the manufacturers nameplate rating and choose one with the highest nominal voltage(if it says 110v dontbuy it as it is probably made from cheap substandard materials)

Just remeber, the higher the voltage,the less consumption.

BTW - since I'm on the subject, a 240 volt device takes 2 hot wires with no nuetral. A 120volt device requires a nuetral to balance the voltage as return current. Where du you think that current goes? Back into your house for use? Hell no!!!! it gets transmitted back to the power company for them to reuse and resell. You should really consider using devices that are run on 240v. Europeans dont have this same problem as alot of their power grids operate at 240v as the standard, Not like the good ole USA capitalists that stay at 120V for a very good reason.