The Atomic ST1 Regulator is another high performance regulator that utilises their flow-through balanced piston first stage and pneumatically balanced second stage but this time the first stage is made out of stainless steel, which delivers virtually the same corrosion resistance as Titanium but at a lower price.

Atomic have used Stainless Steel because it does not require protective chrome or nickel plating processes that can be harmful to the environment and stainless steel is 100% recyclable so that it can be reused when it eventually comes to the end of it usable life. Stainless steel is also better at dissipating the extreme cold generated by the regulator as gas is decompressed into each stage, giving it better cold water performance and reliability than chrome plated brass. Like the rest of the Atomic regulator range the first stage it fitted with five low pressure ports on a swivelling turret and two high pressure ports on the main body

The second stage features all-Titanium components as in the T3 and B2 models for excellent durability and corrosion resistant characteristics. The ST1 features the Atomic seat saving orifice within its pneumatically balanced valve to prolong the life of the low pressure seat, allowing for a two year / 300 dive service period. The second stage is also fitted with a diver adjustable inhalation resistance control and an automatically adjusting venturi vane (AFC) which works to minimise the risk of an unexpected freeflow.