If an item has a related gearset, this is the list of items in that set, and an unlock expression that evaluates to a number representing the progress toward gearset completion (a very rare use for unlock expressions!)
Type: object
Object Properties
The maximum possible number of items that can be collected.
Type: int32
Mapped to Definition
The list of hashes for items in the gearset. Use them to look up DestinyInventoryItemDefinition entries for the items in the set.
Type: array
Array Contents: uint32
Mapped to Manifest Database Definition: Destiny.Definitions.DestinyInventoryItemDefinition