The Cobalt Assembly reputation provides a guaranteed Item Level 389 ring with a special proc! You can get these rings in less than an hour.
Cobalt Assembly Rewards
Cobalt Assembly Reputation
Requirements
You need to be level 70 to unlock the reputation. Then, head to the Cobalt Assembly in Azure span to pick up Welcome to the Assembly and complete the quick quest chain.
Cobalt Assembly
After this, you can start grinding reputation!