Patented Dynamic Adjustment
A common objection to adjustable second stages is that divers can't imagine themselves twisting and turning a knob as they descend and ascend through the depths. If inhalation resistance is set near zero at depth, your ascent would require you to manually increase resistance as ambient water pressure is reduced to prevent free-flow. Taking another stride beyond common second stage engineering, Oceanic designed a patented DYNAMIC ADJUSTMENT feature into the heart of the Delta 4. This mechanically balanced valve maintains a preferred breathing resistance throughout the dive. Set it once and the Delta 4 automatically adjusts to make breathing as easy at 100 feet as it is at 30 feet - with no additional manual adjustment.

Adjustable Venturi System (A.V.S.)
The A.V.S. deflector vane found in the Delta 4 diverts the airflow from the valve directly to the mouthpiece, producing smooth venturi-assisted inhalation. With the addition of a user Adjustable Venturi System (A.V.S.), in the form of a simple yet ingenious switch, full adjustment control rests in the hands of the diver.

Improved Adjustment Mechanisms
Both the Dynamic Adjustment Knob and A.V.S. Switch are designed to be unobtrusive, yet easily manipulated even with the thickest gloves.

Surge Deflector
Our surge protector (the titanium, blue or yellow that you see in the images above) reduces freeflow caused by surge or oncoming current.

Computer optimized design
Oceanic regulators are exclusively designed using the latest 3-D computer modeling techniques. This allows us the ability to model and test performance while still in the early stages of development. The Delta 4's unique deflector vane and housing design diverts airflow from the valve directly to the mouthpiece, producing smooth venturi-assisted inhalation.

Lightweight
The Delta 4's housing is made from an ABS/Polycarbonate composite blend of materials making the Delta 4 both extremely rugged and lightweight (6.7 ounces) and nearly neutrally buoyant underwater, reducing jaw fatigue on extended dives. The extremely ligweight cover ring is machined from a solid piece of aircraft aluminum, and then hard anodized, utilizing a unique process to prevent corrosion.

Patented Orthodontic Mouthpiece
To further reduce jaw fatigue, the Delta 4 features a patented Orthodontic Mouthpiece, designed to accommodate the natural overbite of the human jaw.

Nitrox Compatibility
The Delta 4 is classified as being suitable for use with nitrox breathing gas mixtures containing up to 40% oxygen by volume without the need for special preparation, cleaning or component parts.

FDX-10 Balanced Diaphragm First Stage
Forged from marine-grade brass, the FDX-10 features optimized air paths and angled hose ports for superior performance and comfort. A sealed Balanced Diaphragm design, Enviro Kit and patented DRT TM (Dry Regulator Technology) isolate all internal components from the environment. 2 high pressure and 4 low pressure ports allow convenient and comfortable hose routing.