A Metroid tank barrier is a special containment unit used by the Space Pirates during Metroid Prime 3: Corruption to successfully contain Phazon Metroids, which are normally able to break out of any form of containment. These red-colored barriers are more advanced than the Xenome Containment Units from Metroid Prime and Metroid Prime 2: Echoes, which were easily destroyed with weapons fire. Metroid tank barriers prevent the Metroids from breaking free by exploiting their alternate weakness to sound frequencies by emitting a high-frequency pitch that renders them docile. They are seen in the Metroid Processing room on the Pirate Homeworld, in the Research Facility.
The barriers cannot be destroyed by Samus's weapon fire due to their force field protection. However, they are not entirely indestructible. If Samus removes Energy Cell ID: SN-3871S-7, which is below Metroid Processing, the barriers will lose their power and release the Metroids. The barriers also contain Metroid Eggs, and one of them contains no Metroids, but a Missile Expansion. This barrier can be destroyed to enable collection of the expansion.
"Metroid tank barrier online. Emits a high-frequency pitch that keeps specimens docile."