Check the listing for details. Atomic Aquatics ST1 Second Stage Regulator. Condition: New. Listed at 559.95 USD. Why Stainless Steel & Titanium?Stainless Steel delivers virtually the same corrosion resistance as Titanium at a lower price. Stainless Steel does not require protective chrome or nickel plating processes that can be harmful to the environment and is 100% recyclable. The ST1 second stage features all-Titanium components as in the T2 and B2 models.A Breath of Fresh AirEnvironmentally conscious topside...natural breathing at depthThe ST1 is another industry first from Atomic Aquatics. The use of Stainless Steel means we are doing our part for clean air when divers are out of the water. The legendary Atomic design means divers also breathe easy at depth.Second Stage:All-Titanium second stage construction same as Atomic T2 and B2 modelsPatented Atomic Seat Saving Orifice (Titanium)Patented Atomic Automatic Flow Control (AFC)Rapid adjustment knob for manual second stage de-tuning in special situationsAll-stainless steel Atomic Comfort Swivel standardA new high-flow second stage case lowers breathing effort at any depth from shallow water to beyond the limitsDual material second stage cover enables entire front to be used for purgeDual silicone comfort fit mouthpiece with tear-resistant bite tabs2 year / 300 dive service intervalLimited Lifetime Warranty – not contingent on proof of serviceWide exhaust deflector to disperse bubbles for enhanced visibilityPneumatically-balanced poppet, high-flow case and lever design for easy breathing at all depths and tank pressures.Patented Atomic AFC – Automatic Flow Control.Soft overmolded Rapid Adjustment Knob for manual detuning in special situations such as surf entries or octo use.Patented Atomic Titanium Seat Saving Dynamic Orifice maintains crisp like-new factory tuning and prevents damage during storage.Hose features patented Stainless Steel Atomic Comfort Swivel with Black PVD coating.Dual material second stage cover enables entire front to be used for purge.Elliptical exhaust valve dramatically reduces exhalation effort at depth.Dual silicone comfort fit mouthpiece with tear-resistant bite tabs – both comfortable and durable.