No probs mayday ...
More infos if interested , as per my own experience , one of the two pins can be missing ...(old 747 , but that depends on brake PN).
The length correspond on the "material" who is left on the discs , as i said , depending on the temperature ...
In some docs , you will even find , the number of cycle remaining depending on this length.
In the worst case , a brake can be de-activated , do you follow me ? but then some operational restrictions as runway length , etc.