Oceanic NEO CDX5 w/MaxFlex, Yoke, DVT Regulator Pneumatically balanced second stage with virtually no breathing effort Advanced composite construction for rugged durability and light weight - our lightest second stage at only 5.7 ounces (without hose) Ergonomic Adjustable Venturi Switch (A.V.S.) for simple Dive/Pre-Dive Adjustment Patented Orthodontic Mouthpiece with high-density bite tabs for increased comfort and reduced jaw fatigue Paired with either the FDX-10 or CDX-5 Over-Balanced Diaphragm First Stages with an option to include Oceanic's DVT (Dry Valve Technology) Nitrox compatible to 40% out-of-the-box