Patients often ask what is a follicular unit in the clinic. Follicular unit is a bundle of hairs as shown in the diagram, which consists of 1-4 long hairs and 1-2 fine hairs, sebaceous glands, erector pili, perifollicular vascular plexus, and collagen. The surgical procedures for follicular unit transplantation include FUT (follicular unit transplantation) and FUE (follicular unit extrusion). The way in which follicular units are obtained differs between the two procedures. When such grafts are transplanted, the hair growth is more similar to the original hair growth distribution. When the grafts are too large, the transplanted hairs will have a bundled appearance and the result will not be natural. Of course, if the hair grafts are too small, the grafts will cause too much hair transection damage when splitting the preparation, resulting in too much loss of valuable dominant donor area hairs and subsequently a much lower density of transplanted hairs in the recipient area. 