Cold fusion sewn technique, also known as “genius weft.” The genius weft is a blend of hand-tied wefts and machine-made wefts, combining the advantages of both techniques. It closely resembles hand-tied extensions in that it is very thin, but unlike hand-tied wefts, it can be cut. The genius weft can be trimmed to customize the weft length according to the client’s head. It has no return hair at the root, making the weft ultra-comfortable. A genius weft installation must be maintained every 6 to 10 weeks maximum, depending on hair density. Our bundles contain 50 g of hair. The extensions are reusable and must be installed exclusively by a professional.