Helmets

• Mark VI: Default Unlocked
• CQB: Default Unlocked
• EVA: Complete Campaign on Normal, Heroic, or Legendary
• EOD: Complete Campaign on Legendary
• Hayabusa: Collect all skulls
• Security: Get all achievements in Halo 3.
• Scout: Complete "Used Car Salesman" Achievement
• ODST: Complete "Spartan Graduate" Achievement
• Mark V: Complete "UNSC Spartan" Achievement
• Rogue: Complete "Spartan Officer" Achievement
• Recon: Bungie Employees and selected few.
• Flaming Helmet: Bungie Employees only

Shoulder Pieces

• Mark VI: Default Unlocked
• CQB: Default Unlocked
• EVA: Complete The Ark on Normal, Heroic, or Legendary
• EOD: Complete The Ark on Legendary
• Hayabusa: Collect 9 skulls
• Security: Get 750 of 1000 gamerscore on Halo 3
• Scout: Complete "Mongoose Mowdown" Achievement
• Recon: Bungie Employees and selected few

Chest Armor

• Mark VI: Default Unlocked
• CQB: Default Unlocked
• EVA: Complete Tsavo Highway on Normal, Heroic, or Legendary
• Hayabusa: Collect 5 skulls
• Hayabusa with Katana (Add-On): Earn 1000 out of 1000 Gamerscore Points
• EOD: Complete Tsavo Highway on Legendary
• Scout: Complete "Too Close to the Sun" Achievement
• Recon: Bungie Employees and selected few
• Bungie: Bungie Employees only

ELITES

Helmets

• Combat: Default Unlocked
• Assault: Default Unlocked
• Flight: Complete Campaign on Heroic or Legendary
• Ascetic: Unlock "Steppin' Razor" Achievement
• Commando: Unlock "Overkill" Achievement

Shoulder Armor

• Combat: Default Unlocked
• Assault: Default Unlocked
• Flight: Complete The Ark on Heroic or "The Storm" on Legendary
• Ascetic: Unlock "Overkill" Achievement
• Commando: Unlock "Killing Frenzy" Achievement

Body Armor

• Combat: Default Unlocked
• Assault: Default Unlocked
• Flight: Complete Tsavo Highway on Heroic or Legendary
• Ascetic: Complete "Up Close and Personal" Achievement
• Commando: Complete "Triple Kill" Achievement