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