Vanadium steel

Vanadium Steel is an alloy used by the UNSC in construction of its star ships. Vanadium Steel is not as strong as Titanium-A alloy, and so it is not used as armor plating, but rather in the making of essential and unarmored components. One of the things on ships made of Vanadium Steel is the engine shields and baffles of UNSC Destroyers.

Covenant Spy Probes are designed specifically to blend in perfectly with Vanadium Steel components so that they may fulfill their missions with ease.