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Dear Sifus...

I want to ask... So many VS in the market.. All claim to have effect. But how to know which to use? For example, Pivot Raizin alone got purple, yellow, red, blue and grey... Some other brand they packaged it so small and they claim it is voltage stabilizer.

1. What is the difference? Which is better?
2. And how if we got a counterfeit, does it still work?
3. How do we know that the VS actually does its work and not just display what it wants?
4. For grounding cables...