I use one all the time. There are 2 main products "surge guard" & Progressive industries. You need not only surge protection you need protection against too high or too low voltages. If you are not paying at least $250 you are not buying the right one. In Mexico they are essential, power is not reliable and I am currently leading a caravan where somebody blew the capacitors off their convertor. I also use a voltage regulator. I have never seen these for sale in the US, but they sell them at Home Depots in Mexico. They lower high voltage and raise low voltage to safe levels.