And to add to Falcaros's post, Punch size has become of something of a debate... MOST reputable time tested physicians that perform FUE with consistent results, try to adhere to the smallest punch that provides viable follicular units from 1 to 5 hairs. This small punch size happens to be around 0.75mm. Sometimes a physician might jave to jump to 0.9mm or at the most while very very rare... 1.0mm, however anything larger than 1.0mm is rediculously large and has twice the potential for donor area scarring. than would be with a 0.75mm punch.
If you are asking yourself, who uses this small punch it will be easy for you to find out. AND you will find with research who is still using large punches that now have been deemed as the size or plugs.