Hair extensions using the ultrasound method.
There are two ways to attach extensions with keratin bonds: with a heat iron or with an ultrasound device. The heat iron generates heat and melts the bonds. The ultrasound device, on the other hand, does not work with heat, but with ultrasound waves. The ultrasound waves set the molecules in motion, which causes the keratin to melt. The key advantage of this method is that the keratin is not worked into the hair in a hot state. High heat can damage the hair, which is why many people use the ultrasound method. This is usually more expensive, however, because the ultrasound devices cost several times more than the price of heat irons. Those who want gentle extensions that they can wear permanently shoud usually use tape-ins or nanoring extensions.
