There are flexible protective plates from Luxurious-Haire extensions for attaching Keratin/Wax Extensions. This prevents the scalp from being hit by the heat tongs. You can easily place them around the strands of hair. The plates stay well in place and are made of flexible, transparent plastic.
The number of centimeters is also indicated on the protective plates, so that you can see exactly how much distance you have to the scalp. Place permanent hair extensions safely in the hair.