Diver adjustable inhalation effort 
Most downstream demand valve regulators are calibrated during manufacturing to a single, 'middle of the road' operation. Whether fining up current at 100+ feet or merely snorkelling out to the dive site, this factory adjustment may not be optimum for the wide variety of demands we place on our equipment. A simple twist of the Delta 4.2's adjustment knob enables complete control...set the inhalation requirement to near zero when you need ultimate performance, or tune it for greater resistance 
as conditions or preferences change.

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 4.2. This mechanically balanced valve maintains a preferred breathing resistance throughout the dive. Set it once and the Delta 4.2 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 4.2 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.

Inline Swivel 
 The Delta 4.2 features an ergonomically designed in-line swivel for ultimate comfort.

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 4.2's unique deflector vane and housing design diverts airflow from the valve directly to the mouthpiece, producing smooth venturi-assisted inhalation. 

Lightweight
The Delta 4.2's housing is made from an ABS/Polycarbonate composite blend of materials making the Delta 4.2 both extremely rugged and lightweight (6.7 ounces) and nearly neutrally buoyant underwater, reducing jaw fatigue on extended dives. The extremely lightweight 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 with High-Density Bite Tabs
To further reduce jaw fatigue, the Delta 4.2 features a patented Orthodontic Mouthpiece, designed to accommodate the natural overbite of the human jaw.

• Diver adjustable inhalation effort
• Patented Orthodontic Mouthpiece with high-density bite tabs
• Patented Dynamic Adjustment automatically maintains inhalation effort throughout the dive
• Adjustable Venturi Switch (A.V.S.) for simple Dive/Pre-Dive Adjustment
• Inline ball swivel for reduced jaw fatigue and comfort
• Nitrox compatibility up to 40%
• Now available with Mi-Flex Hose which is a lightweight, flexible, Braided hose designed to outperform and outlive traditional rubber hoses
• Limited Lifetime Service Agreement

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.

Alpha 9 Octopus

Patented orthodontic mouthpiece
To further reduce jaw fatigue, the Alpha 9 features a patented Orthodontic Mouthpiece, designed to accommodate the natural overbite of the human jaw. 

• Designed to perform to the U.S. Navy's Class A standards at 198 feet
• Inexpensive to maintain
• Available with Mi-Flex Hose which is a lightweight, flexible, Braided hose designed to outperform and outlive traditional rubber hoses.
• Integrated Purge Button
• Orthodontic Mouthpiece
• Nitrox compatibility up to 40%
• Weight (without hose) 6 ounces
• Dimensions (front profile) 2.9 inches
• Factory Set Inhalation Effort 1.2—1.4 CIW*
• Limited Lifetime warranty
• Limited Lifetime Service Agreement