SUPERIOR RELIABILITY - The Aqualung Helix DIN regulator features an over-balanced diaphragm 1st stage and pneumatically balanced 2nd stage, ensuring consistent gas delivery at any depth for ultimate dependability. OPTIMIZED BREATHING - Experience effortless inhalation and exhalation with the adjustable Dive/Pre-Dive Venturi switch, minimizing free flow and maximizing breathing comfort during your dive, enhancing overall safety. EXTREME DURABILITY - Crafted with a chrome-plated brass 1st stage and techno-polymer 2nd stage, the Helix regulator withstands harsh underwater conditions, providing long-lasting performance and peace of mind. ENHANCED COMFORT - The lightweight design and silicone components reduce jaw fatigue, while the included octopus with a 39" hose offers a streamlined profile and easy access in emergency situations, improving dive experience. NITROX COMPATIBILITY - Dive with confidence using gas blends up to 40% O2, thanks to the Helix regulator's Nitrox compatibility, expanding your diving options and ensuring safe use with enriched air mixtures. Aqua Lung Helix Regulator & Octo Din