What it is: ghd eclipse Styler, $245What it does: Auto-regulates its temperature—there are no manual controls—so that the plates are evenly heated and hot enough to style your hair, but never too hot that it’ll fry your strands.Why it works: Most flatirons have one heat sensor, right smack in the middle of each plate. Eventually, the whole plate heats up, but the hottest point remains in the middle. And you can (and most people will) twist the temperature dial all the way up to 400+ degrees, to ensure it gets the job done. This is a recipe for disaster that results in running the hot tool over the same strands multiple times to get your coveted style, and with temps that high, hair damage is inevitable.ghd’s new styler’s revolutionary technology includes not one, but three heat sensors along each plate, which keeps the whole thing at the same temperature. This handy tool’s loaded with convenient specs: heats up in under 20 seconds, automatically switches off after 30 minutes of no use, insulated so you don’t burn your hands every two minutes, works to straighten, curl and wave hair. But the coolest feature of all is its auto temperature control. The temp maxes out at 365, which is optimum for effective styling—and stops you from giving in to the urge to crank it up to hair-singing levels.Why you care: Almost one-quarter of YouBeauty readers who took our Healthy Hair Quiz said they use a flatiron two or more times a week. Most other hot tools allow you to reach dangerously high temps. This one will make styling less damaging and more efficient.