... type of hair extension systems, for keratin silky straight hair,pre-bonded hair, hair bonding, nail hair, stick hair and Flat-tip hair extension.4. Two types of hair extension iron ... heads ize: 12", 14", 16", 18", 20", 22", 24"Hair color: black, dark / medium / light brown, blond available Loof Fushion Hair Connector Hair Extension Tools