Aeris Scuba Regulator with Octopus, Scuba Dive Gear Aeris A1 Regulator - Nitrox compatible to 40% (the recreational limits of nitrox), Lightweight 2nd stage to prevent jaw fatigue and add to overall comfort Orthodontic mouthpiece to alleviate jaw fatigue by easing bite needed to hold regulator Aeris A1 Octo - Streamline flat design, Large Purge button, Tuned to resist unwanted freeflows Bright