This lightweight Mares Dual Adj Octopus is made of techno-polymer features an oversized silicone purge button so that the purge button is easy to push. All Mares second stages are a reliable downstream valve design and offer the unique patented Vortex Assisted Design (VAD) system. The air bypass tube conveys air to the mouthpiece creating a swirling vortex with a low-pressure area in the center that keeps the diaphragm down during inhalation, for very sensitive and easy breathing at all depths. This pneumatically assisted designed (P.A.D.) safe second is equipped with an adjustable breathing knob for the ultimate in breathing comfort. Adjustable features a breathing resistance control knob on the left side of the regulator. Optimum performance is delivered when the knob is turned all the way out (counterclockwise when looking at the knob). For specific situations in which you require a higher breathing resistance, turn the knob clockwise to add compression to the spring acting on the demand valve. Furthermore, the compact and ergonomic exhaust tee ensures superior hydrodynamic performance and reduced exhalation resistance. The mouthpiece is made of soft hypoallergenic silicone: limiting jaw fatigue and offering a secure fit even after very long dives. Mares developed the Superflex hose after many years of testing and research. The results achieved far surpassed the tests required by EN250. Hose is extremely light weight and exceptionally soft, guaranteeing the maximum freedom of movement and further reducing jaw fatigue. The regulator comes with a high visibility yellow Superflex hose that is a 3/8" threaded high flow hose and is 39.4" (100cm) in length. The regulators total weight is 12.6 oz. (357 g) with hose. Regulator is Nitrox ready up to 40% oxygen out-of-the-box.