Hot melt glue. We use premium Italian keratin to create our extensions. Each strand weighs 1g. Installation is done strand by strand. Our keratin locks can easily be cut in half to create mini keratin locks. This technique must be performed by a professional and is suitable for several hair types. The duration of keratin installations varies approximately depending on hair density, generally 2 to 5 months. Our envelopes contain 25 strands for a total of 25g, or 1g per strand.