Negative ions have been a longtime fan favorite in the hair care industry, and it is no surprise that this same technology would appear in our top picks for the best hair straightener. Negative ions have been found to reduce static and frizz while locking in moisture, and the same goes for your hair when you use the CHI Air Expert Classic Tourmaline Ceramic Flat Iron!
We usually roll our eyes at oil-infused heat tools — but you can actually watch this oil being sucked right out of the refillable cartridge in the handle. When you press the iron closed over your strands, the oil vapor seeps through tiny holes to condition and straighten your hair. And don't worry fine-haired friends: It made our tester's hair silkier, but not like she'd dipped it in an oil vat.