How do Mjolnir armory lockers work in Halo Infinite?

After completing the second mission, Foundation, you’re let loose upon Halo Infinite’s open world. Soon after being introduced to this more open-ended structure, you’ll notice Mjolnir armory icons while exploring Zeta Halo. Considering that the game doesn’t explain these beforehand, how do these armory locations work? 

Mjolnir armory lockers are stationary lockers scattered around the Halo Infinite map, found through exploration or exposed by taking over FOB’s. All you have to do is walk up to any of the lockers and interact with them by holding X on an Xbox controller. Some lockers will feature enemy ambushes; meanwhile, others are unattended, so always be prepared to fight if there’s opposition.

Interacting with the locker unlocks a multiplayer cosmetic, which cannot be viewed while playing the campaign. You’ll have to return to the main menu and access the armor hall from the customization screen to view your unlocked cosmetics.

The armor hall doesn’t tell you which specific cosmetics coincide with which lockers. However, you’ll at least know which cosmetics are obtainable only through the story. Any locked customization item’s description will read “Available in Halo Infinite’s campaign” to denote its acquisition through the Mjolnir armory lockers.