Is this hair straightener safe to use on SYNTHETIC hair?
Yes, it works on synthetic wigs that can take heat (just dont have the heat on too high).
Occasionally want to change to straight hair after perming, will this hair straightening tool destroy the permed shape?
No, it wont permanently strip the hairstyle, curly hairstyle will back after washing.
What about the P button?
Its a preset button, quickly adjust to 240℉, 360℉, 450℉. Help you choose the right temperature range.
Is this hair iron dual voltage?
Yes, it is. And you dont need to adjust the voltage by hand, it will auto adjust according to the actually voltage. You just need a plug converter when you abroad.
Why does the product description say there are 12 temperature levels, but some reviews say there are only 3?
Because it has 3 preset temp by pressing the P button: 240℉, 360℉, 450℉, you could find the temp range you want via the preset temperature, and press the plus and minus buttons to adjust, each press changes 20℉. Its total 12 temp settings.