Regulate the 2 IN 1 straightener's temperatures between 150°C-230°C/300°F-450°F You know what your hair can handle: -Thick hair: 190°C-230°C/380°F-450°F - Curly, stubborn hair: 170°C-230°C/340°F-450°F - Chemically treated hair: 150°C-170°C/300°F-340°F...