A follicular unit is identified anatomically as a small bundle consisting of one to four hair follicles (typically 2.2 to 2.8 hairs), full-thickness as well as fine hairs, and the oil glands, muscles, and connecting tissue that accompany and support hair follicles. If you look carefully at a closely-clipped scalp from above (just as you would, for example, at a wheat field from an airplane), you can see that scalp hair does not grow in even distribution like wheat in a field, but rather in little groups of hairs that seem to be clumped together. These little groupings of hairs are called follicular units (FUs). When the scalp is examined under a magnifying glass or microscope, these follicular units look like islands. The islands are rooted at a level beneath the skin surface, called the mid-dermis. Identifying an individual follicular unit can be difficult when follicles grow at angles under the skin and surface in the midst of neighboring follicular units. The identification, harvesting, and transplanting of follicular units require the training and skill of a hair restoration physician and specialist.