U Tip/Nail Tip is a type of :
Human hair extension that is shaped like a U and is applied to the hair by heating up, it is also called “Fusion” hair extensions. U Tip/Nail Tip Hair Extensions are fitted using a heat connector to melt the keratin tip against small sections of natural hair. The melted keratin is then rolled around the natural hair tightly so that it forms a fully sealed bond. Keratin heats and cools very quickly, allowing for easy application. The heat from a hair extension iron will not damage the hair, it’s less hot than a standard curling or flat iron and the hair extension iron only touches the hair for a few seconds.