Equips in any weapon slot, but it is not itself a weapon. Unlocks in the following order: 1) Equipped in Heavy Weapon slot: allows user to equip a Non-Exotic Hand Cannon in lieu of a Secondary Weapon. 2) Adds ability to equip a Scout or Pulse Rifle in lieu of a Secondary Weapon (Non-Exotic). 3) Allows user to equip ANY non-Exotic Primary in place of a Secondary weapon. 4) User may equip 2 Exotic Primary weapons at the same time. Requires an Exotic shard to unlock. 5) FINAL UPGRADE: Requires another Exotic shard to unlock; the Harness may be equipped in any weapon slot, and allows the user to equip an Exotic weapon in each of the other two slots. For example, fully leveled, you could equip Ice Breaker and Thunderlord, MIDA and Gjallarhorn, or Suros Regime and Invective. The catch is that you would carry ONLY 2 weapons; the upside is that they are both extremely powerful. I think something like this would be a way to let characters carry 2 exotics without totally unbalancing PvP, and the cost in shards would make it meaningful. You could even have it cost an exotic shard at EACH step to unlock. Hey, let's go with that. Any opinions? (Bungie, you can use this idea, I won't sue.)