Use without Power Cord: Cordless hair straightener brush is built-in rechargeable battery, a great replacement for traditional hair iron brush. It supports up to 20 minutes for cord-free run time. No need to find a socket, you could use it anytime and anywhere, super suitable for traveling, urgent dating and so on. NOTE: Don't use it while charging. One Key to shift temperature: Easy to control the straightening brush in one button to adjust two temp level: 170 degrees Celsius/338 degrees Fahrenheit, 190 degrees Celsius/374 degrees Fahrenheit, to style softer and harder hair type. Scientific temperature setting will not cause any hair burn. Press and hold the switch for 2 seconds to turn on, and press the switch to choose temperature, it can heat up quickly in 10s. Heating Technology: is metal ceramic heater, ceramic heating, better thermostat effect. Ceramic heating elements are more energy-saving, and give even heat distribution and quick temperature recovery time. In just one minute, It can heat up to the desired temperature and offer great results. Auto-off Function: The straightening comb comes with auto-off function, to ensure maximum safety, optimum performance and save energy. The appliance is switched to ON for more than 15 minutes, it will automatically switch off if not used. NOTE: press ON/OFF Mode button for 2 seconds to restart. Anti-scald Design: Designed with anti-scald brush teeth, YAPOY hair straightening brush can effectively protect you from every angle, allows you to enjoy straightening and styling your hair without worries from getting burned or shocked by the heat. You can literally put the hair straightener on scalp and feel nothing.