Apalus Hair straightener brush is designed for easy hair caring. It is a technology-breaking product with innovation. Temperature setting guide: Auto constant temperature at 365℉ for delicate colored fine hair; Customized set 410℉ for natural texture hair; Customized set 450℉ for thick or wavy hair; Centigrade to Fahrenheit convert: press “+””-“at same time US safety Plug, Short-Circuit Protection, Leakage Protection, Auto shut-off protection if NOT IN USE for 60 minutes. Dual voltage operation support: 110V~240V,Travel International use: need an extra international power plug adapter User tips: Also, here is some tips for you to avoid pulling your hair bad when you use it. 1. Please keep hair dry and neatly groomed before using. 2. Please use a normal brush to divide the intertwined hair before straightning. 3. Section your hair into 4-8 sections, and use our straightener brush one section per time. 4. Pull the bottom of your hair with the other hand and straight your hair with our brush. 5. We suggest to comb the hair slowly for 5 seconds each time. Please don’t use it more than 10 seconds, your hair doesn’t like it.