From Halopedia, the Halo wiki
KEYSTONE was one of several armor projects undertaken by the Office of Naval Intelligence, designed to test the ever-evolving standard for the third generation of powered armor systems. The project was initiated as an evolutionary design study and later combined with elements seen on earlier iterations of the Mark VII project such as the GEN1 specification employed by Naomi-010 and the DECIMATOR for GEN2.
The KEYSTONE helmet was made available for use in Halo 4 as an armor permutation as part of the game's inclusion in Halo: The Master Chief Collection. The helmet is available as part of Series 7: Elite, as an Exchange-exclusive item. The helmet is free to unlock for all players, and costs 0 to purchase. It was never available in Halo 4 for Xbox 360.
|Piece||Description||Unlock requirements (Halo 4)||Unlock requirements (Halo: MCC)|
|Materials Group evolutionary design study that eventually formed the basis of the production Mk. VII.||N/A (MCC-exclusive)||Series 7: Elite, Purchase in The Exchange ( 0)|
A Spartan-IV wearing the Keystone helmet with the Eternal armor effect.
List of appearances
- Halo 4 (First appearance; Halo: The Master Chief Collection-only)
- Halo Waypoint, Canon Fodder - Despite Distance (Retrieved on Jun 17, 2021) [archive]
- Halo Waypoint, Official Cosplay Guide: Mark VII: Page 3 (Retrieved on Jun 15, 2021) [archive]
- Halo Waypoint, Canon Fodder - Parallel Threads (Retrieved on Jun 25, 2021) [archive]
- Twitter, Halo (@Halo): "Make sure it fits just right. Next week in MCC with the arrival of Season 7, don't miss your chance to grab the #HaloInfinite Inspired Mk. VII Helmet for Halo 4." (Retrieved on Jun 17, 2021) [archive]