From Guild Wars 2 Wiki
Supplies is an Event item for the renown heart challenge Help Zara secure and supply Gallant's Folly in Gauntlet Gulch in Mount Maelstrom.“
Someone in the nearby Pact base to the north would like this.
— In-game description
Supplies are found inside Dropped Supplies all around Gauntlet Gulch.
- As they have merchant value, any remaining ones after the renown hear has been completed can be sold to any merchant for a bit of coin instead being destroyed.
- They can still be obtained after their related renown heart has been completed.
- Each one delivered to Zara will provide 5% of total renown heart progress, so 20 will fully complete it.