option for fusion attachments is using hair which is pre-tipped with a keratin adhesive. A heat clamp is then used to melt the adhesive to attach the extension hair to the natural hair. Fusion weave allows washing hair frequently and the use of regular hair products such as hair gels. This technique is very time consuming taking 3 or more hours. They need re-positioning every 2–3 months as the natural hair grows. Due to various chemicals in the glue, which may cause hair loss and scalp irritation, combined with heat, this method is more damaging to natural hair. Micro ring (also known as micro-bead or micro loop) hair extensions use small metal rings or beads (usually aluminum) and can sometimes be lined with silicone to attach the extension hair. They are fixed to small sections of natural hair and tightened using a special tool that clamps the bead around the natural hair. The micro-beads are designed to be small enough so that they are not visible in normal use. They need re-positioning every two to three months as the natural hair grows and the micro-beads move away from the scalp. As they do not use heat or adhesives, these hair extensions should cause less damage than some types of extensions, if placed correctly and properly taken care of. Today, there are many sizes available for micro rings/beads from about . The sizing makes a difference on the weight of the extensions, the feel, and the visibility. Some micro-beads are so tiny that they mimic a non-surgical hair transplant. The stylist installing the extensions should determine what size of micro rings/beads is best for the client's hair length and texture, prior to installation on the head. Netting is a technique which involves braiding natural tresses under a thin, breathable net that serves as a flat surface onto which stylists can weave extensions. This method requires the use of hair net or cap to be placed over the person's hair that has been braided. Netting provides more flexibility than track placement because the stylist is not limited to sewing extensions to a braid. With netting there is the option of sewing the hair wefts onto the net or gluing. This technique is not as time-consuming when compared to the other hair techniques because it takes about 2–4 hours to complete. The most recent development in weave extensions is lace fronts, which are