Regulator First Stages Only

Your regulator is one of the main pieces of scuba equipment that allows you to breathe while underwater. The first stage attaches to the diver's tank via a Yoke or DIN fitting. It regulates the air pressure as the air exits the tank before the air can enter the air hose.

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.

Price From: $169.95

Regulator First Stages Only

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
  • Environmentally Sealed
  • Marine Grade Chromed Brass Material
  • Compact Design
  • Lightweight 29 oz (822.14 g)
  • Nitrox Ready Up to 40% Out-of-the-Box

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