First Stage

Compact machined first stage based on the expedition-tested Apeks DS4 platform. Engineered to reduce ice-related free-flow and improve performance in cold-water conditions.

• Innovative over-moulded first-stage endcap and environmental diaphragm help prevent ice build-up that can cause free flow in extreme conditions and protect the first stage from impact damage.
• Large surface-area heat exchanger diaphragm clamp increases the gas temperature inside the first stage, resulting in improved cold-water performance.
• Unique over-balanced diaphragm design: as the diver descends, the over-balancing feature allows the medium-pressure gas in the hose to increase at a faster rate than ambient, providing superior performance at depth.
• Ports: 2 high-pressure (HP) ports and 4 medium-pressure (MP) ports.