Gender Mounting information be found on this page - Gender Mounting Instructions

You need to know what Gender Changers you will be installing so you know what mounting hardware you'll need.
Female to Females come with stock Jack Screws & stock Hex Nuts.
Male to Males & Female to Males only come with stock Jack Screws (No Hex Nuts).

For Female to Female:  You'll need the Jack Screws below and you can use the stock hex nut.
For Male to Male - Male to Female - Female to Male: You'll need the Jack Screws and Hex Nuts below.

Remember - Each Gender Changer requires 2 Jack Screws & 2 Hex Nuts.
It is very easy to over-tighten and strip the threads so you may want a few extras!