Plug keys are key items that can be used to open doors and unlock certain areas. Plugs function like keycards or tech cards except they can be reused over and over. Press Use on a plug socket to insert a plug key if you have one or extract it, however, doing so will lock off area again.
Plug keys can come in 3 colors: blue, red and yellow.
Blue Plug Key
Red Plug Key
Yellow Plug Key
Plug Keys can be found in the Revolution and the Ghost Ship missions.
