FUE (Follicle Unit Extraction) question

Hello everyone. I have a question about the FUE (Follicle Unit Extraction) method of hair transplantation.

I understand how the follicular unit is inserted with a “Choi Implanter Pen” or “Implanter pen”. I understand how it works and I’m okway with it.
But I can’t find out anything about the device which is used to collect the follicular units which is used by the implanter pen later on.
What is it called? Where can I learn more about it?
I’d like to know as much as I can about the procedure and the devices used and how they work before deciding what transplantation method to use.
Thank you!