Keratin is a protein that is naturally in your hair Keratin bonded hair extensions come in the form of U-Tips which are strands of hair that are pre-bonded with high quality Italian keratin. To attach the keratin bond extensions to you natural hair, they are melted with a special low heat keratin extension iron and is then wrapped around the natural hair to create a bond, this bond Is created is super strong yet nearly undetectable, no one will know you’re wearing them!