This is one of the best flattening irons you can buy it heats up very quickly. In fact I left it on too long as my own one takes forever to heat up and it shut itself off. So yes the automatic shut off works I actually love having the piece of mind knowing that it shuts off after 30 mins. Sometimes my 13 year old daughter will borrow my hair iron and I have to double check to make sure she didn't leave it on. Btw I have very thick coarse wavy hair and this flattening iron did a fantastic job my hair also felt very silky and not damaged. This is hands down the best flattening iron I have owned used.
Straighteners work because they have flat plates that get hot and touch together on either side of your hair. By doing that, they put heat through your hair follicles, trap in moisture and take out frizz. The plates on a flat iron can be made of several different materials, and they’re good for different uses. The best iron for you varies depending on the type of hair you have, the type of styling you want to do, and the amount of heat your hair needs.
I read lots of different reviews about these straighteners and a lot said these aren't genuine. They are definitely ghds just professional ones which means they are lighter. They are exactly the same ones at my hair dressers. I'm happy.