Cold fusion weft technique, also known as "genius weft". Genius weft is a blend of hand-made and machine-made wefts, offering the benefits of each technique. It is very similar to hand-tied wefts, being very thin, but they can be cut unlike hand-tied weft. The genius weft can be cut to customize the length of the wefts according to the customer's head. It does not have any hair return at the roots, which makes the weft ultra comfortable. A genius weft installation should be maintained every 6 to 10 weeks maximum, depending on hair density. Our envelopes contain 50g of hair. The extensions are reusable and must absolutely be installed one by one