Your regulator is one of the main pieces of scuba equipment that allows you to breathe while underwater. The second stage contains the mouthpiece and purge valve; the purpose of the second stage is to deliver the air into the diver's mouth and to remove any waste (air or other objects) as needed.
Purge Button/Exhaust Valve
The 2nd stage's exhaust valve is a one-way valve that allows the diver's exhaled air to leave the regulator. Basically, it is where the bubbles exit the mouthpiece.
The purge button allows the diver to force air from his/her tank through the regulator to clear any water that may have inadvertently entered the 2nd stage. This button should be fairly simple to manipulate, even when wearing thick dive gloves. It should also only require the pressure from one finger to successfully perform the purge.
Your 2nd stage's mouthpiece is a more crucial piece of equipment than most people believe. A mouthpiece should be comfortable in your mouth; if it feels too big or too small, use a different size mouthpiece.
Choose your AERIS Second Stage.
The A2 second stage is low-profile, durable, lightweight, and a great performer at a great price. The A2 first stage is designed to be easy to maintain and service, and is known by divers and technicians worldwide. AERIS 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 A2's second stage unique deflector vane and housing design diverts airflow from the valve directly to the mouthpiece, producing smooth venturi-assisted inhalation.
The A2's housing is made from an ABS/Polycarbonate composite blend of materials making the A2 both extremely rugged and lightweight, weighing 6 oz (170 g) 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. The A2 has a small profile with a front diameter of 2.9' (7.4 cm), and now comes with a MaxFlex Hose which is a 30' (76.2 cm) lightweight, flexible, braided hose designed to outperform and outlive traditional rubber hoses. To further reduce jaw fatigue, the A2 features a patented Orthodontic Mouthpiece, designed to accommodate the natural overbite of the human jaw. The A2 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.
The ION second stage is the latest iteration of the flagship Aeris ION Regulator Line. The ION has a swivel and by adding an ultra-flexible braided MaxFlex hose makes it one comfortable regulator. The pneumatically balanced demand valve of the Ion Second Stage along with a highly responsive design allows this regulator to provide a high volume of airflow with even the slightest inhalation effort, making it seem nearly effortless to breathe at any depth. All in a second stage barely wider than the mouthpiece. The ION means business as it comes equipped for any type of dive conditions, cold or warm. Following the rules of the sea, or should we say the rules of the C: Compact - Comfortable - Customizable; the ION is a diver's dream.
A2 Second Stage Features:
Downstream Demand Valve
Venturi Control Switch for Dive/Pre-Dive Adjustment
Patented Orthodontic Mouthpiece
Diameter 2.9' (7.4 cm) and Weighs 6 oz (170 g)
ABS/Polycarbonate Composite with Anodized Aluminum Ring
ION Second Stage Features:
Pneumatically Balanced Second Stage
Virtually No Breathing Effort
Patented Dynamic Adjustment Automatically Maintains Inhalation Effort
Adjustable Venturi Switch for Dive/Pre-Dive Adjustment
Ultra-Flexible Braided MaxFlex Hose with Swivel
No Inline Swivel for Reduced Weight
Patented Orthodontic Mouthpiece with High Density Bite Tabs
ABS/Polycarbonate Composite Blend Construction
Lightweight: 5.4 oz (153 g)
Compact: 2.3' (5.8 cm) Diameter
Aircraft Anodized Aluminum Cover Ring
Dry Valve Technology (DVT)
DVT is a revolutionary regulator technology designed to automatically eliminate moisture and contaminants from entering your first stage, even if the dust cap is accidentally left off.
DVT eliminates corrosion of critical internal components, bacteria, hose deterioration, and damaged gauges and computers.
Pneumatically Balanced Valve
The pneumatically balanced second stage reduces breathing resistance to near zero with a balanced valve seat designed to respond to the slightest inhalation.
A pneumatically balanced second stage actually has (or can have) the same initial crack opening effort as a mechanically balanced, but the spring force of a pneumatically balanced second stage is lighter so it’s spring rate is also lower.
Diver Adjustable Inhalation Effort
A simple twist of the 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.
Choose your AERIS First Stage.
The A2 first stage is low-profile, durable, lightweight, and a great performer at a great price. It has one high pressure port and four low pressure ports to accommodate most hose arrangements. The A2 first stage is designed to be easy to maintain and service, and is known by divers and technicians worldwide. This first stage is manufactured from marine grade chrome plated brass and utilizes a non-balanced flow-by piston design and weighs 26 oz (737 g). An optional patented design also puts an end to flooded regulators without sacrificing performance! DVT (Dry Valve technology) is a revolutionary regulator technology designed to automatically prevent moisture and contaminants from entering your first stage, even if the dust cap is left off.
The AT600 is a High Performance First Stage with Environmental Seal. The diaphragm membrane transmits the pressure changes to the internal mechanism eliminating the need for the surrounding water to enter the intricate mechanism. The benefit of this type of first stage design is that none of the internal parts are exposed to contaminants such as salt, sand, chlorine or pool acids. These environmental contaminants cause corrosion and mineral deposits to form on the internal mechanism deteriorating regulator performance. The standard Diaphragm Regulator does allow water into the mainspring chamber so that the diaphragm can perform this transmission of pressure changes.
With the AT600 there is a Secondary Environmental Diaphragm Membrane that seals off the spring chamber keeping the first stage completely sealed off from the environment adding a second layer of corrosion resistance.
The first stage has 4 Low Pressure Ports (LP) and one High Pressure Ports (HP) and is Nitrox compatible to 40% out of the box.
A2 First Stage Features:
Non-Balance Flow-By Piston First Stage
Nitrox Compatible to 40%
4 LP Ports, 1 HP Ports
Marine Grade Chromed Brass Material
Weighs 26 oz (737 g)
DVT Eliminates Corrosion/Contamination of Critical Internal Components
AT600 First Stage Features:
AT 600 Over-Balanced Diaphragm First Stage
4 LP Ports
1 HP Ports
Marine Grade Chromed Brass Material
Lightweight 29 oz (822.14 g)
Nitrox Ready Up to 40% Out-of-the-Box
Din vs. Yoke
Yoke couplings are more commonly found world wide and are almost always used by the ever-popular aluminum 80 tanks.
DIN fittings are safer than yoke fittings and are the only fitting that can couple with high-pressure tanks. The advantage of DIN fittings is that they screw into the tank valve and trap the high-pressure o-ring so it cannot protrude, which can occasionally happen when using a yoke fitting.