Follicular Unit Extraction (FUE) and Direct Hair Implantation (DHI) are two of the most popular methods of hair transplantation. The main difference between the two is that with the FUE method, the recipient is located before the graft is implanted, whereas, with the DHI method, spotting and grafting are done simultaneously with the Choi implant pen, providing complete control of depth, allowing the direction and angle of placement of each hair transplant.