HSI Professional Glider Ceramic Tourmaline Ionic Flat Iron This HSI Professional Glider Ceramic Tourmaline Ionic Flat Iron ($38) is the bestsellling option on the whole site, with a whopping 32,000 reviews. Customers love that all it takes is one pass to get their hair straight. Image Source: amazon.com HSI Professional Glider Ceramic Tourmaline Ionic Flat Iron $38 from amazon.com Buy Now