The infobox template in this article is missing some required data. You can help Nukapedia by filling it in.
Z4K-97B is a hostile synth encountered in the Institute's reactor room during the quest The Nuclear Option with any faction. Z4K-97B, along with A-2018 and XPN-20A, will serve as the game's final boss during all endings other than the Institute ending.
Interactions with the player character
|This character is involved in quests.|
- Z4K-97B wears a special variant of the synth armor which is jet black in color and can be shot off by focus fire and explosives, much like power armor.
- Z4K-97B will always spawn as a legendary enemy.
Z4K-97B appears only in Fallout 4.