Popsugar Beauty Hair Extensions Keratin Hair Extensions Review What It's Really Like to Get Hair Extensions 3 June, 2018 by Nancy Einhart View On One Page Photo 9 of 14 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 9 Ultrasonic gun Rather than bond the keratin tips with heat, RPZL uses a special ultrasonic wave gun. So there was no heat and no pain, just a quick "click" from the gun as each piece was attached. Previous Next Start Slideshow Hair ExtensionsLong HairstylesBeauty TipsHair