XL4 STAGE3

Compact regulator built on the expedition-proven Apeks DS4 first-stage platform. Engineered for reliable cold-water performance, impact protection, and comfortable long-duration use.

First stage

• Compact machined first stage based on the Apeks DS4 platform.
• Innovative over-moulded first-stage endcap and environmental diaphragm to help prevent ice build-up and protect the first stage from impact damage.
• Large surface-area heat exchanger diaphragm clamp increases gas temperature inside the first stage for improved cold-water performance.
• Over-balanced diaphragm design allows medium-pressure gas in the hose to increase faster than ambient as depth increases, improving performance at depth.
• Ports: 2 high-pressure (HP) ports and 4 medium-pressure (MP) ports.

Second stage

• Compact, lightweight second stage for improved comfort and reduced jaw fatigue on long dives.
• Large heat exchanger for improved cold-water performance and freezing resistance.
• High-performance pneumatically balanced, lever-operated poppet valve.
• Large over-moulded, self-flushing and controllable purge button.
• Ergonomic Venturi lever that is easy to use and locate.
• Flexible nylon-braided hose for better cold-water performance than traditional rubber hose; standard metallic hose connection for interchangeability.
• Comfo-bite mouthpiece with a unique bridge that fits across the upper palate and does not require bite pressure to stay in place; reusable mouthpiece clip for easy field changes.
• Durable, flexible rubber exhaust tee for effective bubble diversion.
• UV inhibitors in white materials to help prevent discolouration.