Is there a difference between 4mm and 5mm?

I made 4mm in Gangnam 5 days ago. But I can't feel it's high..I'd like to use 5mm Is there a big difference between 4mm and 5mm? And at the beginning, the chief executive showed me 4mm and said if she wanted a higher one, she said she would look at something else, but I tried one before the operation. ..... I can't remember if the nurse said 4mm.. Is it because of anesthesia? ;; If you decide to use 4mm, is it correct to use 4mm in the operating room? Even if I ask you how many mm you put in the treatment right now, do you know for sure? ㅜㅜ Please let me know the difference between 4mm and 5mm . !