External Command Network Module

The External Command Network Module or CNM, is an external attachment to MJOLNIR Powered Assault Armor helmets.

Two different models are known, one designed for the Military Police helmet and the other for the Mark V[B] helmet. The former is standard issue to Special Force unit commanders, while the latter is used by Beta-5 Security units patrolling the Inner Colonies.

The CNM is available as a helmet attachment in Halo: Reach.