The most significant difference between DHI from the FUE method is the tools used for the operation. Instead of punches, "needles," which are called Choi pen, are mainly used. Choi pens come in various sizes. The hair transplant surgeon decides on the pen's width, which will be used according to the patient.

Choi pens enable a more precise extraction operation where the Choi pen penetrates the skin, collects the follicles, and leaves the skin with minimal disturbance in the surrounding area. Using them removes the risk of holes forming on the scalp, which is a possible disadvantageous effect in the FUE technique. Since the DHI least invasive method of hair transplant so far, it does not leave scar marks regardless of its success.