A:Answer I'm not an electrician, so I defer to experts. But this product is NOT a voltage transformer/converter. Thus, if your hair waver is a "single voltage" device (i.e., it does not have its own voltage transformer/converter or a switch to go back and forth between 100~120V/200~250V), then I would not recommend using this product. Since your hair waver is 250V and almost all electric outlets in the US are 110-120V, it will not function properly without a voltage transformer/converter. Most voltage transformers/converters are much more expensive than this product, which is merely a plug adapter. Hope this helps.