Keratin Fusion extensions are a great way to add length and highlights. A simple way to achieve natural looking, long hair on any hair type. Keratin Fusion can be used on an average 6 months. It is a piece by piece method, 40 pieces come in a pack. The hair is tipped with keratin and heated and hardened to your own hair. The quality of the extensions and the quality of the installation will determine the longevity of pre-bonded extensions.