Hot Hardware published a review on the Lenovo Yoga 3 Pro, Watchband Hinge And Intel Core M Deliver Thin And Light Performance A quote from the article:

We recently go our hands dirty, so to speak, with the new Core M 5Y70 Broadwell-powered Lenovo Yoga 3 Pro ultrabook. Contrary to Intel's design goal with Broadwell, the Yoga 3 Pro is not a fanless design, but instead is a super-thin, ultra-light convertible ultrabook with a premium, high resolution 3K display with a crisp 3200x1800 native resolution. And though the Yoga 3 Pro is crazy-thin and light at just 2.6 pounds, its cooling fans are barely audible under load. In addition, this machine has a design feature that is a first for notebooks. Its "watchband" style hinge allows the machine to flip and contort all the way back into tablet mode and anywhere in between--and look good while doing it...

 Lenovo Yoga 3 Pro, Watchband Hinge And Intel Core M Deliver Thin And Light Performance @ HotHardware.com