The dark eco box, also known as the dark eco crate, is an explosive item in The Precursor Legacy, and will damage Jak upon contact with it. It consists mostly of yellow edges and corners, with light gray sides. On every side is a symbol which resembles the radiation warning symbol as most things that contain or pertain to dark eco.
These boxes contain dangerous and highly-explosive dark eco supplies, mainly used to stop Jak and anyone else trying to enter certain areas. In locations where one can use the A-Grav Zoomer they are stacked in a 23 block. The boxes can be destroyed with yellow or red eco without harming Jak. In Lava Tube, there are also large barrels of dark eco which can be destroyed with yellow eco.
They are often found in places where Jak can use the A-Grav Zoomer including Fire Canyon, Precursor Basin, Mountain Pass, and Lava Tube. They are also found in Forbidden Jungle, lost Precursor city, Snowy Mountain, and Spider Cave.