Atomic Aquatics Z2 Octopus: ;Precision-Built to Perform-as-Perfectly as its Primary Model;Factory-Rated for Oxygen-Enriched Mixtures Up to 40%;Demand Valve Body: Zirconium Plated Brass;Critical Metal Components of Demand Valve: Titanium or 316 Stainless Steel, Completely-Corrosion-Proof